TL;DR: The Fuxi (Early Heaven) arrangement depicts an ideal, symmetrical yin-yang cosmic order tied to the River Map (Hà Đồ), while the King Wen (Later Heaven) arrangement depicts the world of actual change and movement tied to the Luo Shu (Lạc Thư), the version most commonly used in practical feng shui.
What are the two Bagua arrangements?
In the I Ching tradition, the eight Bagua trigrams do not have only one arrangement. There are two main systems, tied to two legends and two different purposes: Pre-Heaven Bagua (also called Fu Xi Bagua) and Post-Heaven Bagua (also called King Wen Bagua). Distinguishing these two charts matters greatly, because they place different trigrams in the same direction, which leads to different interpretations if they are confused.
What is Pre-Heaven Bagua (Fu Xi Bagua)?
According to legend, Pre-Heaven Bagua was created by King Fu Xi (one of the Three Sovereigns of ancient China), based on his observation of the He Tu, a diagram said to have appeared on the back of a dragon horse emerging from the Yellow River. This is the Bagua chart of "substance", describing the primordial, ideal and still state of the universe before all things moved and transformed.
The outstanding feature of Pre-Heaven Bagua is the perfect symmetry between pairs of opposing trigrams:
| Pair of opposing trigrams | Axis of opposition |
|---|---|
| Qian (Heaven) opposite Kun (Earth) | South - North |
| Li (Fire) opposite Kan (Water) | East - West |
| Zhen (Thunder) opposite Xun (Wind) | diagonal |
| Gen (Mountain) opposite Dui (Lake) | diagonal |
This arrangement expresses the law of balanced yin and yang, forces that oppose yet complement each other in a harmonious, still way.
Pre-Heaven Bagua is used mainly in the study of yin-yang philosophy, as the theoretical foundation for the structure of the 64 I Ching hexagrams, and in some feng shui schools as the "substance" layer (the theoretical base) placed beneath the compass, supporting deeper readings of qi and the hidden relationships between directions, rather than being used directly to determine practical orientation.
What is Post-Heaven Bagua (King Wen Bagua)?
Post-Heaven Bagua is said to have been rearranged by King Wen of Zhou, based on the Luo Shu, a diagram on the back of a divine turtle emerging from the Luo River. This is the Bagua chart of "function", describing the world after all things have been born and have begun to move and change ceaselessly through the cycle of the four seasons.
In Post-Heaven Bagua, the positions of the trigrams are tied directly to the eight directions and to the yearly cycle of qi:
| Trigram | Direction |
|---|---|
| Li (Fire) | South |
| Kan (Water) | North |
| Zhen (Thunder) | East |
| Dui (Lake) | West |
| Xun (Wind) | Southeast |
| Kun (Earth) | Southwest |
| Qian (Heaven) | Northwest |
| Gen (Mountain) | Northeast |
This arrangement is not perfectly symmetrical like Pre-Heaven. Instead it reflects the real sequence of growth, flourishing and decline of qi, like the journey of a day, a year or a human life.
When is each chart used?
Because Post-Heaven Bagua describes the world of phenomena and real movement, it is the chart most widely used in applied feng shui: determining the orientation of a home, calculating Ba Zhai (East Four Mansions, West Four Mansions), setting up the Nine Palaces Flying Stars, and many divination methods such as Qi Men Dun Jia. When a feng shui student says "the Qian direction" or "the Li palace", they are using positions according to Post-Heaven.
Pre-Heaven Bagua, by contrast, leans toward philosophical reasoning and academic study: explaining the origin of yin and yang, serving as the basis of reasoning for certain advanced techniques in Xuan Kong feng shui (such as determining the correspondence of mountain and facing, and the hidden properties of dragon veins), and providing the foundation for understanding the deeper meaning of the trigrams in the I Ching before those trigrams are applied to life through Post-Heaven.
