Most feng shui introductions begin with the eight-direction map — the chart behind “wealth corner” and “career direction.” That map is downstream of something older: eight three-line symbols, each a different stacking of a solid and a broken line — the yin and yang pair — that are the working vocabulary of the I Ching, of feng shui direction-reading, and of Chinese divination generally. The eight trigrams (八卦, bāguà) are what this page lays out: how the symbols are built, the full table of names, images, elements and family roles, the classical passages the table comes from, the difference between the pre-heaven and post-heaven arrangements, and how a trigram is actually read.
What the eight trigrams are#
Two kinds of line, stacked three high. A solid line is yang; a broken line is yin. Read from the bottom up, three positions with two possible lines each give 2 × 2 × 2 = 8 possible stacks, and each stack is one trigram (卦, guà):
乾 qián ☰ — three solid · 兑 duì ☱ — broken at the top · 离 lí ☲ — broken in the middle · 震 zhèn ☳ — solid at the bottom only · 巽 xùn ☴ — broken at the bottom only · 坎 kǎn ☵ — solid in the middle · 艮 gèn ☶ — solid at the top only · 坤 kūn ☷ — three broken
Eight trigrams, no more and no fewer — the count is arithmetic, not convention. Tradition reads a generative ladder into the same arithmetic — taiji, the two forms, the four images, the eight trigrams, and at six lines the sixty-four hexagrams — a sequence the Yin and Yang page quotes from the Book of Changes; the eight are that system’s first complete alphabet, and everything above them — the sixty-four hexagrams of the I Ching, the direction wheel of feng shui — is built by stacking and arranging these eight.
Eight trigrams meaning: the full table#
The table below is the reference most readers come for. Rows run in the pre-heaven sequence 乾一兑二离三震四巽五坎六艮七坤八 — qian one, dui two, li three — the numbering later casting methods use; the direction column is post-heaven. Every column has a classical source, not a modern committee: the natural images and the family roles are recorded in the Shuogua (《说卦传》, “Discussion of the Trigrams”), the ancient commentary appended to the Book of Changes, and the passages behind them are quoted in the sections that follow.
| Trigram | Symbol | Natural image | Element | Family role | Direction |
|---|---|---|---|---|---|
| 乾 Qián | ☰ | heaven | metal | father | northwest |
| 兑 Duì | ☱ | lake | metal | youngest daughter | west |
| 离 Lí | ☲ | fire | fire | middle daughter | south |
| 震 Zhèn | ☳ | thunder | wood | eldest son | east |
| 巽 Xùn | ☴ | wind | wood | eldest daughter | southeast |
| 坎 Kǎn | ☵ | water | water | middle son | north |
| 艮 Gèn | ☶ | mountain | earth | youngest son | northeast |
| 坤 Kūn | ☷ | earth | earth | mother | southwest |
The element column runs on the five phases — metal, fire, wood, water, earth — with fire and water matching their own images and the other six trigrams carrying the rest. The direction column is the post-heaven arrangement, the one feng shui actually works with; how it differs from the pre-heaven order is a question of its own, taken up below.
Nature and body: two more rows from the Shuogua#
The Shuogua does not stop at images and family roles. Two of its lists add a layer most English-language tables skip — each trigram’s one-word nature and its seat in the human body:
乾,健也。坤,顺也。震,动也。巽,入也。坎,陷也。离,丽也。艮,止也。兑,说也。 “Qian is strength; Kun is compliance; Zhen is stirring; Xun is entering; Kan is sinking in; Li is clinging to light; Gen is stopping; Dui is joy.”
乾为首,坤为腹,震为足,巽为股,坎为耳,离为目,艮为手,兑为口。 “Qian is the head; Kun the belly; Zhen the feet; Xun the thighs; Kan the ears; Li the eyes; Gen the hands; Dui the mouth.”
Read together as a table:
| Trigram | Nature | In the body |
|---|---|---|
| 乾 Qián | strength | the head |
| 兑 Duì | joy | the mouth |
| 离 Lí | clinging to light | the eyes |
| 震 Zhèn | stirring | the feet |
| 巽 Xùn | entering | the thighs |
| 坎 Kǎn | sinking in | the ears |
| 艮 Gèn | stopping | the hands |
| 坤 Kūn | compliance | the belly |
These two rows are not trivia; they are the working layer. A trigram’s nature — its operating tendency — is where the images extend from, as the next section shows.
The family: father, mother, and six children#
The family column is the part English-language tables most often present as arbitrary. It is not. The Shuogua derives the six children from the two parents in a single passage:
乾,天也,故称乎父。坤,地也,故称乎母。震一索而得男,故谓之长男。巽一索而得女,故谓之长女。坎再索而得男,故谓之中男。离再索而得女,故谓之中女。艮三索而得男,故谓之少男。兑三索而得女,故谓之少女。 “Qian is heaven, and so is called the father; Kun is earth, and so is called the mother. Zhen — at the first asking a son was obtained, and it is called the eldest son. Xun — at the first asking, a daughter: the eldest daughter. Kan — at the second asking, a son: the middle son. Li — at the second asking, a daughter: the middle daughter. Gen — at the third asking, a son: the youngest son. Dui — at the third asking, a daughter: the youngest daughter.”
Read the line patterns and the model is visible in the symbols themselves. The six children are Qian and Kun exchanging lines: one yang line entering Kun’s three yin makes a son — at the bottom it is Zhen (eldest), in the middle Kan, at the top Gen — and one yin line entering Qian’s three yang makes a daughter — bottom Xun, middle Li, top Dui. A structural note the Xici makes in passing completes the pattern: the sons are the trigrams with more yin lines than yang, the daughters more yang than yin — one active line moving through a receptive field. Nothing in the family column is decoration; it is a line-exchange model of generation drawn on the trigrams themselves.
Pre-heaven and post-heaven: the two arrangements#
The most common confusion about the eight trigrams is why there are two different arrangements of them on the compass — the pre-heaven (先天, Fuxi) and the post-heaven (后天, King Wen) orders. The older passage, again from the Shuogua:
天地定位,山泽通气,雷风相薄,水火不相射,八卦相错。 “Heaven and earth fix the positions; mountain and lake connect their breath; thunder and wind press upon each other; water and fire do not shoot at each other; the eight trigrams interlock.”
This is the pre-heaven arrangement: four opposite pairs set facing one another — heaven (Qian, south) against earth (Kun, north), fire (Li, east) against water (Kan, west), lake (Dui, southeast) against mountain (Gen, northwest), thunder (Zhen, northeast) against wind (Xun, southwest). It is a diagram of relationship — how the eight balance and answer one another — and tradition treats it as the structure (体, “the body”) of the system. The pre-heaven sequence qian-one through kun-eight, which later casting methods use to number the trigrams, comes from this order.
The post-heaven arrangement keeps the same eight symbols and re-seats them by the compass they govern in applied work — Zhen east, Xun southeast, Li south, Kun southwest, Dui west, Qian northwest, Kan north, Gen northeast. Its source is another Shuogua passage — “the sovereign issues forth from Zhen” (帝出乎震) — which walks the eight around the compass through the seasons of the year; the full walk, and the direction–trigram–element table built on it, is laid out in Feng Shui Bagua Map Explained. This is the use (用): the arrangement feng shui, date selection, and the divination arts actually work with. Structure versus use is the whole of the difference — same eight symbols, one arranged by relationship, one by working direction. One further connection worth knowing: in the post-heaven order each trigram also carries a number from the Lo Shu square — Kan 1, Kun 2, Zhen 3, Xun 4, Qian 6, Dui 7, Gen 8, Li 9 — which is where the “trigram numbers” of feng shui literature come from.
How a trigram is read: image first#
None of these tables is read like a dictionary. A trigram is a cluster of images around a tendency, and the tradition’s word for the method is quxiang (取象), “taking the image.” Take Kan, water. Its nature in the table above is “sinking in,” and its images extend from there: water, the gorge, the pit, the trap — hardship, the difficult passage in an I Ching reading — and, in the body row, the ear, a hollow that takes things in. The classical lists assign each trigram dozens of such images; later commentaries argue over each attribution, but the working rule is the tendency: water runs down and fills low places, and everything that runs down and fills low places belongs, in this system, to Kan.
The same method joins the columns of the main table. A direction is not good or bad in itself but read through its trigram; a trigram is read through its images; the images extend from the trigram’s nature. When a feng shui text speaks of the north as water and an I Ching reading speaks of the abyss, both are reading the same three-line symbol.
Where the trigrams do work#
In the I Ching. Stack two trigrams, one above the other, and you get a hexagram — eight times eight, sixty-four. The eight trigrams are the alphabet of the book, and every hexagram is read through its two components: the lower trigram as the inner, earlier side of the situation, the upper as its outer, later development.
In feng shui. The post-heaven arrangement, laid over a floor plan or a compass, is the bagua map — the direction–trigram–element table behind “wealth corner” and the rest of direction-reading. How the compass schools differ over it is laid out in What Is Feng Shui.
At the door. The most literal form the eight trigrams take in daily life is the bagua mirror (八卦镜) — the octagonal mirror hung above doorways in Chinatowns worldwide, the eight trigrams ringed around a mirror center. It is these eight symbols in their most retail form.
A note for overseas readers#
The count eight is not numerology; it is combinatorics. Three positions, two states: exactly eight symbols — which is why the trigrams map cleanly onto three-digit binary numbers, solid and broken lines read as 1s and 0s. When Leibniz published his explanation of binary arithmetic in 1703, the paper cited the hexagram figures that the Jesuit missionary Joachim Bouvet had sent him from China, and Leibniz read the line-pairs as binary digits — the most famous meeting between this system and Western mathematics. He did not need the diagram to invent binary arithmetic; the correspondence was, to him, a confirmation that the Chinese sages had been working with 0s and 1s all along.
Two cautions for English-language readers. First, the Western “bagua map” of popular feng shui books — the Black Hat (BTB) chart oriented by the entrance door rather than the compass — descends from the post-heaven table but usually drops the trigram and element layers, keeping only the corner labels; what it kept and what it left out is laid out in the bagua map article. Second, the word bagua names the eight symbols as a set; in English use a “bagua” is usually the map or the mirror, not one trigram — for a single symbol, say trigram.
Further reading: Feng Shui Bagua Map Explained · The Chinese Five Elements · The Lo Shu Square and He Tu · What Is the I Ching · Back to the Foundations section.