Chinese astrology

A sky turned into arithmetic

Babylonian and Hellenistic astrology read the physical positions of the planets against the constellations of the zodiac. Chinese astrology began in the same way, with court astronomers watching real planets, but over a thousand years it moved the sky indoors. Constellations gave way to cycles, planets to numbered phases, and the visible heavens to a calendar of sixty stem-and-branch pairs that can be computed for any hour without looking up. The two systems practitioners now mean by Chinese astrology, BaZi (the Four Pillars of Destiny) and Zi Wei Dou Shu (Purple Star Astrology), are the end of that process. Neither needs a telescope. Both read time.

Heaven's warnings to the ruler

For most of the first millennium BCE, watching the sky was a matter of state. The universe was pictured as one organism in which the court and the heavens answered each other, so an eclipse, a comet or an unseasonable frost was read as a message to the sovereign about how he was governing. Sima Qian, the Han court's Grand Scribe and Astrologer (c. 145–86 BCE), set out this view in the Book of Celestial Offices (Tianguan shu) inside his Records of the Grand Historian: the point of observing Heaven was to understand where Heaven ends and man begins, and how history changes. The doctrine of heavenly warning also worked as a brake on the throne. A ruler who governed badly could expect the sky to say so.

The founding case is political. In 1059 BCE the five visible planets gathered unusually close together in the region of the sky the Chinese assigned to the Vermilion Bird, in what Western astronomy calls Cancer. Modern calculation confirms the event. The Zhou read it as Heaven transferring its mandate (Tianming) to them, and used it to justify the conquest of the Shang. From then on, reading the planets was a guarded state skill. The silk manuscript Divination by the Five Planets (Wuxing zhan), sealed in a Mawangdui tomb in 168 BCE, shows what that skill looked like: tables of planetary positions and retrograde motion, each tied to omens for war and harvest.

Canopy, egg and empty space

Chinese astronomers argued over the shape of the cosmos long before any foreign model arrived. The Gai Tian, or canopy heaven, pictured the sky as a dome over a flat earth ringed by water, with the sun tracing wider or narrower circles to make the seasons. The Hun Tian, or enveloping heaven, made the cosmos an egg: the earth is the yolk and the sky a full sphere turning around it. The Han polymath Zhang Heng (78–139 CE) built a water-driven armillary sphere to demonstrate it. A third school, the Xuan Ye, held that the heavens were empty and without limit, with the sun, moon and stars floating freely and each moving by its own nature. Texts such as the Huainanzi (139 BCE) and Yang Xiong's Tai Xuan Jing (2 BCE) speak of nine heavens, which some later accounts arrange as layers rising from the Moon through the planets to the lunar mansions and the empty expanse beyond.

Whatever the shape, the five visible planets were each bound to one of the five phases: Jupiter to Wood, Mars to Fire, Saturn to Earth, Venus to Metal and Mercury to Water. The Chinese names still say so. Jupiter is the Wood Star, Venus the Metal Star.

The Five Phases and the rise of dynasties

In the late Warring States period (481–221 BCE) the focus shifted from observation to correlation. The philosopher Zou Yan taught that history moves through the Five Phases (wuxing), Water, Earth, Wood, Metal and Fire, each overcoming the one before it, and that every dynasty rules under one phase until the next displaces it. These phases are stages of change, not physical materials. When the Qin unified China and replaced the Zhou, whose phase was Fire, its ruler took Water, the phase that overcomes Fire, and matched the court's colours, numbers and rituals to it. Yin and yang, the two polarities, completed the frame. Chinese astrology has kept this vocabulary ever since: a chart is a balance of phases and polarities, and the question is always which one is strong, which weak, and what moves between them.

Lunar mansions and a Jupiter that isn't there

The sky itself was divided into a band of twenty-eight lunar mansions (xiu), unequal segments measured along the celestial equator, from a couple of degrees wide to more than thirty. Together they tracked the Moon's monthly passage. Over the Zhou period the mansions turned from a set of star groups into a numbered sequence, a grid for measuring time more than a map of stars.

The clearest example of this abstraction is Tai Sui, the Grand Year. Jupiter takes about twelve years to circle the sky, so the Chinese used its position to name the years. But the real period is about 11.86 years, and it drifts against the twelve Earthly Branches used in the ritual calendar. The astronomers' answer was to invent a planet. Tai Sui is an invisible body that moves at Jupiter's average speed in the opposite direction and completes an exact circuit every twelve years. Years were named by Tai Sui, not by Jupiter. Folk practice still speaks of offending the Tai Sui in a year whose branch clashes with one's own, a direct survival of the counter-Jupiter.

Stems, branches and the cycle of sixty

The engine of Chinese astrology is the sexagenary cycle. Ten Heavenly Stems, the five phases each in a yang and a yin form, are paired in turn with twelve Earthly Branches, the branches that the zodiac animals later came to stand for. Because ten and twelve meet again only after sixty steps, the pairs form a cycle of sixty, called the Jiazi after its first pair. The Shang already counted days this way on their oracle bones. Later the same cycle was applied to years, months and two-hour periods, so every moment can be written as four stem-branch pairs. That is where BaZi, the eight characters, gets its name.

Indian mathematics at the Tang court

The Tang dynasty (618–907) was open to foreign learning, and Buddhism brought Indian astronomers to the capital. Gautama Siddha (Qutan Xida) presented the Jiuzhi calendar in 718, introducing the Indian Navagraha, the nine planets, and compiled the Kaiyuan Zhanjing, a vast treatise on astrology that preserves a translation of Indian sine tables in the tradition of Aryabhata. The mathematics was absorbed. The purpose was not: astrology at court still served the stability of the state and stayed inside the Imperial Astronomical Bureau (Qintianjian).

Ming and Yun: the blueprint and the weather

Two words sit under both BaZi and Zi Wei Dou Shu, and English usually blurs them into fate. Ming (命) is what a person starts with: family, constitution, native aptitudes and blind spots, the conditions in place at the first breath. It is fixed. Yun (运) is movement, the run of luck across a lifetime: the changing conditions a person passes through. It is where timing and choice come in, and it decides when a potential written into the Ming finds the conditions to show itself.

The tradition insists the two work only together. A saying often quoted by practitioners puts it this way: Ming without Yun is a carriage with no road, and Yun without Ming is a road with no carriage. A chart read in this spirit is a map of terrain, not a verdict. Knowing the Ming shows where a person's natural strengths lie. Knowing the Yun shows when to push, when to hold back and when to change direction. Effort in a favourable period is said to go with the wind; the same effort in an obstructive period calls for caution and patience. The ideal is An Ming, being at rest with one's fate, which means understanding it well enough to use it.

BaZi: from the Year Pillar to the Day Master

BaZi reads the elemental climate of the moment of birth from the four stem-branch pairs of the year, month, day and hour. It ignores the visible sky entirely.

Its history turns on one change. Under the Tang, Li Xu Zhong worked with three pillars, year, month and day, and read destiny mainly through the Year Pillar, which fits a society where standing came from lineage. In the tenth century Xu Zi Ping added the hour to make four pillars. He also moved the centre of the reading to the Heavenly Stem of the Day Pillar, the Day Master (日主). From then on the Day Master stood for the self, and every other character in the chart was read by its relationship to it. The shift coincided with the Song civil-service examinations, which let a person rise by merit rather than birth, and the method still carries his name as Zi Ping BaZi. The Day Master approach was set down in the classics practitioners still study: the Yuan Hai Zi Ping, the San Ming Tong Hui, the Zi Ping Zhen Quan and the Di Tian Sui.

The hidden stems

Each pillar has a Heavenly Stem on top, the visible energy, and an Earthly Branch below, the ground it stands on. The ten stems are single forces, such as yang Wood or yin Fire. The twelve branches are mixtures: under each zodiac animal lie one to three hidden stems (cang gan), a main qi and, in most branches, a middle and a residual qi. A classical line puts it that the stems move without rest while the branches stay still, holding energy in store.

A chart's real balance of elements cannot be counted without them. Three of the four cardinal branches, Zi, Mao and You, hold a single stem, a concentrated energy; Wu holds Ding Fire with Ji Earth beneath it. The four storage branches, Chen, Xu, Chou and Wei, each hold three stems and are called graves because what they contain stays locked away until a clash in a later luck period opens them.

The Ten Gods

The Ten Gods (shi shen) are not deities. They are ten relationships, each defined by how another stem's element and polarity relate to the Day Master through the generating and controlling cycles of the Five Phases. They turn a table of elements into a story about a person.

The gods check one another. A chart under heavy Seven Killings needs Eating God to answer the pressure, or Resource to absorb it and turn it into learning and endurance. The classical warning Shang Guan Jian Guan, Hurting Officer meeting Direct Officer, describes the rebellious output element attacking the element of order and rank, and is read as conflict with authority and legal trouble. The Di Tian Sui treats finding the Useful God (Yong Shen), the one element that brings a chart's strength and temperature into balance, as the core skill of the art.

Harmonies and clashes

The four branches of a chart also act on each other through clashes, punishments, destructions and harmonies. The Six Harmonies (liu he) pair branches that attract and, under the right conditions, combine into a new element:

• Zi (Rat) and Chou (Ox) combine into Earth.
• Yin (Tiger) and Hai (Pig) combine into Wood.
• Mao (Rabbit) and Xu (Dog) combine into Fire.
• Chen (Dragon) and You (Rooster) combine into Metal.
• Si (Snake) and Shen (Monkey) combine into Water.
• Wu (Horse) and Wei (Goat) combine into Fire, or Earth in some schools.

The Yuan Hai Zi Ping attaches a condition. If the month of birth, the season that governs the whole chart, does not support the new element, the combination does not transform. It is read as a close bond or a working alliance between the two branches, not as a change in the chart's elements.

The symbolic stars

Alongside the arithmetic of the phases, BaZi uses Shen Sha, symbolic stars. They are not real stars. Each is a rule: when certain stems and branches meet in a chart, the star is said to be present. The best known:

• Tian Yi Gui Ren, the Heavenly Noble, the most favourable of them: help from mentors and institutions when it is needed. It does not prevent hardship; it means a person is not left to face it alone.
• Tao Hua, Peach Blossom, from the cardinal branches Zi, Wu, Mao and You: charm, stage presence and romantic appeal. In a disciplined chart it makes a public figure; in a disordered one it points to entanglement.
• Yi Ma, the Traveling Horse, from the growth branches Yin, Shen, Si and Hai: movement, trade across borders, emigration and restlessness with routine.
• Wen Chang, the Academic Star: quick learning, success in examinations and clear expression.
• Gu Chen and Gua Su, the Solitary and Widow stars: a need for independence and long solitary work. Older texts read them as bad for marriage; modern readers often see the self-directed thinker.

Classical authors argued over how much weight they carry. The purists treat them as adjectives on top of the structure set by the Day Master and the Ten Gods. A Noble star does not rescue a chart under severe clash, and Peach Blossom does not promise a happy marriage if the Spouse Palace, the branch of the Day Pillar, is under attack.

Clock time, solar time and the southern sky

As BaZi spread beyond China, two technical disputes grew. The first is time. The Chinese calendar follows the 24 solar terms, fixed by the sun's position on the ecliptic, so practitioners adjust the recorded birth time for longitude and the equation of time. Beijing time covers all of China: a clock reading of 23:10 in Shanghai falls in the late Zi (Rat) hour, but the same clock reading in western Xinjiang corresponds to a true solar time a little after 20:00, which is the Xu (Dog) hour. An uncorrected birth time can give the wrong Hour Pillar and a different reading.

The second is the southern hemisphere. Because the Month Pillar sets the seasonal climate of the whole chart, some modern practitioners reverse it for southern births, moving it six branches so that a birth in the northern summer month of Wu (Horse) in Australia is charted as the winter month of Zi (Rat). Traditionalists answer that the calendar tracks the sun's cycle, which is the same for everyone, and needs no local inversion. The question remains open.

Zi Wei Dou Shu: the imperial star map

If BaZi describes the climate of a life, Zi Wei Dou Shu, Purple Star Astrology, maps its rooms. Legend credits the Tang immortal Lü Dongbin and the Song Daoist Chen Tuan (c. 871–989), but no Song manuscript survives to support the story. The system's documented anchor is the Ming compilation Zi Wei Dou Shu Quan Shu, published by the scholar Luo Hongxian around 1550. It was long associated with the Imperial Astronomical Bureau and the fortunes of the court, and it reached the general public much later than BaZi.

A chart is a square grid of twelve palaces, one for each Earthly Branch, assigned to areas of life according to the month and hour of birth:

The Life Palace fixes the character, and the other eleven describe its surroundings. A separate Body Palace (Shen Gong) is laid over one of the twelve and stands for the self a person builds through effort and experience, increasingly important in later life.

The fourteen major stars

About a hundred stars are placed in the grid by calculation from the birth data. None is a real star. The fourteen major stars, grouped into the Northern and Southern Dippers, carry the reading:

A star's brightness in a given palace changes how it behaves, on a scale from Temple, its strongest and most constructive, down to Fallen, its most strained. Stars are also never read alone. The method of the Three Directions and Four Squares (San Fang Si Zheng) reads a palace together with the palace opposite and the two that form a triangle with it, so the Career Palace is always judged alongside Wealth and Life.

The Four Transformations and the ten-year limits

If the stars are the cast and the palaces the stage, the Four Transformations (Si Hua) are the script. Each Heavenly Stem, of the birth year or of a current period, transforms four particular stars:

• Hua Lu, prosperity: ease, income, good beginnings.
• Hua Quan, power: drive, control, achievement through effort.
• Hua Ke, fame: reputation, study, grace, problems settled gently.
• Hua Ji, obstruction: friction, delay, the area of life that needs the most care.

Timing comes from the Da Xian, the Grand Limits, ten-year periods that move through the palaces. At each new decade the transformations are recalculated from the stem of the palace now in force. If a decade's Hua Ji falls in the natal Wealth Palace, the reading points to financial strain over those ten years and advises caution with money.

Two modern schools

In the twentieth century, masters in Hong Kong and Taiwan codified rival methods. The San He, or Three Harmonies, school, represented by Wang Tingzhi of the Zhongzhou school, reads the chart's fixed layout: the strength of the major stars, the supporting stars such as the Left and Right Assistants, and the six malefic stars within the triangular relationships between palaces. It is used above all for character and for the overall shape of a life. The Fei Xing, or Flying Star, school, associated with Taiwanese practice and teachers such as Zhang Yaowen, follows the Four Transformations as they fly from palace to palace across the decade, year and month, including the self-transformation of palaces (gong wei zi hua). It puts the chain of transformations ahead of the personality of the stars and aims at dating specific events.

BaZi and Zi Wei side by side

The two systems share their foundations, the sexagenary cycle and the Five Phases, and differ in method. BaZi treats a life as a climate. Through the Day Master, the hidden stems and the Ten Gods it shows the drives, pressures and balance of elements behind a person's choices, the why. Zi Wei Dou Shu treats a life as an administration of twelve departments. Through its palaces and stars it shows where those forces play out, in career, marriage, money or health, the what and the where. Many practitioners use both. Neither claims that the outcome is fixed: both separate the Ming a person is born with from the Yun they move through, and both are meant as guides to timing and self-knowledge.

How to read this section

The chapter cards above run from the court astronomers of the Zhou to the Flying Star masters of modern Taiwan, and the figures below mark the people who built each stage. Read the early chapters for the cosmology, the middle ones for BaZi and the later ones for Zi Wei Dou Shu. Chinese astrology, its history and its methods are available in the fifty-two languages of the Tarot Academy ecosystem. Like every tradition on this site, it is presented as a tool for reflection, not a substitute for professional advice.