Heavenly Stems and Earthly Branches: The Five Elements

The term 天干地支五行 refers to the combination of the ten Heavenly Stems, the twelve Earthly Branches, and the Five Phases as they are assigned within Chinese calendrical and divinatory systems. The Stems and Branches form the sixty-term sexagenary cycle, while the Five Phases—Wood, Fire, Earth, Metal, and Water—provide one layer of qualitative classification applied to those terms. This entry summarizes the standard assignments, their directional and seasonal associations, the treatment of the Earth Branches at the end of each season, the differing rules for yin and yang, and the status of these correspondences as conventions rather than derived conclusions.

天干的五行按次序两两相配

The ten Heavenly Stems are paired with the Five Phases in order. 甲 and 乙 belong to Wood, 丙 and 丁 belong to Fire, 戊 and 己 belong to Earth, 庚 and 辛 belong to Metal, and 壬 and 癸 belong to Water. Within each pair, the first Stem is counted as yang and the second as yin. Thus 甲 is yang Wood and 乙 is yin Wood, 丙 is yang Fire and 丁 is yin Fire, 戊 is yang Earth and 己 is yin Earth, 庚 is yang Metal and 辛 is yin Metal, and 壬 is yang Water and 癸 is yin Water. The assignment follows the sequence of the Stems, so the Five Phases repeat once across the full set of ten.

地支的五行跟着方位与季节

The twelve Earthly Branches receive their Five Phase assignments partly through direction and season. 寅 and 卯 belong to Wood, 巳 and 午 belong to Fire, 申 and 酉 belong to Metal, and 亥 and 子 belong to Water. The remaining four Branches—辰，戌，丑, and 未—belong to Earth. In this scheme, each non-Earth Phase is represented by two Branches, while Earth is represented by four Branches placed at the transitional points between the other four.

The Branches are also grouped by direction and season. 寅，卯, and 辰 form the Wood assembly, associated with the east and with spring. 巳，午, and 未 form the Fire assembly, associated with the south and with summer. 申，酉, and 戌 form the Metal assembly, associated with the west and with autumn. 亥，子, and 丑 form the Water assembly, associated with the north and with winter. These groupings are called 三会, or the Three Combinations. A 三会 is the gathering of three Branches belonging to the same direction. In the system of Branch relationships, the combining force of a 三会 is treated as the strongest among the recognized combinations.

四季之末为什么都归土

辰，戌，丑, and 未 are placed at the end of the four seasons. Their primary nature is Earth, but each of them also stores a residual qi of another Phase. For this reason they are called the four storages or the four tombs. The function of these Branches is not simply to represent Earth in isolation; they are understood as points where the qi of a departing season is retained as it gives way to the next. This storage function is the reason they are sometimes described as 四库 or 四墓, with the terminology depending on context and interpretive purpose.

Because these four Branches are positioned at the seasonal transitions, they operate differently from the other eight Branches. The other Branches correspond more directly to a single Phase and a single direction. 辰，戌，丑, and 未 belong to Earth by their primary assignment, but their stored qi introduces a second layer of meaning. The exact content of that stored qi is treated as a matter of Branch-internal structure rather than as a separate directional or seasonal category.

阴阳在两边的分法不同

The yin-yang division of the Stems and the Branches follows different rules. For the Heavenly Stems, yin and yang are assigned according to their sequence. 甲，丙，戊，庚, and 壬 are yang; 乙，丁，己，辛, and 癸 are yin. Since the Stems are arranged in pairs by Phase, this produces one yang Stem and one yin Stem for each Phase.

For the Earthly Branches, yin and yang are assigned according to their ordinal position. The Branches occupying odd-numbered positions are yang, and those occupying even-numbered positions are yin. Under this rule, 子，寅，辰，午，申, and 戌 are yang, while 丑，卯，巳，未，酉, and 亥 are yin. The result is that yin and yang alternate across the sequence of Branches, and each Phase does not necessarily receive one yang Branch and one yin Branch in a simple paired arrangement. The difference between the two rules means that a Stem and a Branch sharing the same Phase do not necessarily share the same yin-yang status.

这套归属是约定，不是推导出来的结论

The Five Phase assignments of the Stems and Branches are conventional. They form part of the received framework of Chinese metaphysics, but they are not derived from a single independent principle that would allow the whole system to be reconstructed by deduction. The assignments can be described, listed, and applied, but they should not be presented as the necessary outcome of a more basic theory. Different branches of Chinese cosmology and calendrical studies use these correspondences in different ways, and the rules given here represent one standard arrangement rather than a universal proof.

A related distinction concerns the levels at which the Stems and Branches operate. The Heavenly Stems are positioned above and are called the Heavenly Origin, or 天元. Their qi is treated as outwardly manifest. The Earthly Branches are positioned below and internally contain the Human Origin, or 人元. Each Branch is said to hide from one to three Heavenly Stems within it, and the influence of these hidden Stems is understood to operate at a deeper or less visible level than the Stem that appears openly. This distinction between the manifest qi of the Stems and the concealed qi of the Branches is part of the standard interpretative framework.

Another layer of Five Phase terminology is 纳音. 纳音 assigns a separate Five Phase designation to each of the sixty sexagenary combinations. These designations are not the same as the Five Phase assignments of the individual Stems and Branches. 纳音 belongs to a different system of classification and is not interchangeable with Stem or Branch Five Phase. In this site’s chart output, 纳音 is shown for reference only. Core analysis does not use 纳音 as its basis. The primary Five Phase reading relies on the Stem assignments, the Branch assignments, and their interactions, while 纳音 remains a supplementary label attached to the sixty-cycle terms.