Heavenly Stems and Earthly Branches
Definition
Heavenly Stems (天干, tiāngān) are the ten stem signs (甲 to 癸) carrying yin/yang and Five Elements (五行, wǔxíng). Earthly Branches (地支, dìzhī) are the twelve branch signs (子 to 亥) linked to animals, clock hours, and elemental climates. BaZi pairs one stem with one branch in each pillar.
Ten Heavenly Stems (天干)
Stems are the “sky” layer: ten names repeating in order. Yang stems (甲丙戊庚壬) and yin stems (乙丁己辛癸) alternate, and each maps to an element pair (Wood, Fire, Earth, Metal, Water). The Day pillar’s stem is always your Day Master (日主, rìzhǔ).
| Stem | Chinese | Pinyin | Element | Polarity |
|---|---|---|---|---|
| Jia | 甲 | jiǎ | Wood | Yang |
| Yi | 乙 | yǐ | Wood | Yin |
| Bing | 丙 | bǐng | Fire | Yang |
| Ding | 丁 | dīng | Fire | Yin |
| Wu | 戊 | wù | Earth | Yang |
| Ji | 己 | jǐ | Earth | Yin |
| Geng | 庚 | gēng | Metal | Yang |
| Xin | 辛 | xīn | Metal | Yin |
| Ren | 壬 | rén | Water | Yang |
| Gui | 癸 | guǐ | Water | Yin |
Twelve Earthly Branches (地支)
Branches are the “earth” layer: twelve names tied to animals, double hours, and month branches in solar-term BaZi. The animal you quote from horoscopes is usually the Year branch, not the whole chart.
| Branch | Chinese | Pinyin | Animal | Element cue |
|---|---|---|---|---|
| Zi | 子 | zǐ | Rat | Water |
| Chou | 丑 | chǒu | Ox | Earth |
| Yin | 寅 | yín | Tiger | Wood |
| Mao | 卯 | mǎo | Rabbit | Wood |
| Chen | 辰 | chén | Dragon | Earth |
| Si | 巳 | sì | Snake | Fire |
| Wu | 午 | wǔ | Horse | Fire |
| Wei | 未 | wèi | Goat | Earth |
| Shen | 申 | shēn | Monkey | Metal |
| You | 酉 | yǒu | Rooster | Metal |
| Xu | 戌 | xū | Dog | Earth |
| Hai | 亥 | hài | Pig | Water |
The sexagenary cycle (六十甲子)
Stems and branches combine in a 60-count rhythm: 甲子, 乙丑, 丙寅… until 癸亥, then the cycle repeats. Year, Month, Day, and Hour pillars each occupy one pair from this cycle. Luck Pillars (大运) also advance stem-branch pairs in order. See Luck Pillars.
How pillars use them
Each BaZi pillar is stem + branch. A Month pillar might read 丙寅: stem 丙 (Yang Fire) over branch 寅 (Tiger, Wood season). Readers ask how 丙 Fire behaves inside a Tiger month, not either glyph alone.
Branches also anchor hour pillars: two-hour windows from 子时 (Zi, late night) through 亥时 (Hai). Near boundaries, true solar time and Zi-day rules matter.
Hidden stems (conceptual note)
Full chart software often lists hidden stems inside each branch. Beginners can start with visible pillar stems; intermediate readers add hidden stems when counting element strength. This site keeps tables at the visible layer; apps show the full stack.
Related guides
FAQ
How many stems and branches are there?
Ten Heavenly Stems and twelve Earthly Branches. Their 60-pair cycle (甲子…) is the sexagenary cycle (六十甲子, liùshí jiǎzǐ) used across Chinese calendrics.
Which stem is the Day Master?
Whichever Heavenly Stem sits on the Day pillar. Browse profiles on the Day Master hub at /day-master.
Why do branches have animals and hours?
Branches bundle several traditional correspondences: zodiac animals, double-hour periods, seasonal months in the branch cycle, and hidden stem tables in full BaZi software.
Do stems and branches always share the same element?
No. Each stem has a primary element and polarity; each branch carries its own element cue and often hides additional stems inside. Readers weigh both visible stem and branch climate.
Where do I see stems and branches together?
On every BaZi pillar: Year, Month, Day, and Hour each show one stem over one branch. See How to read a BaZi chart for the workflow.
BaZi is a traditional Chinese metaphysics system shared here for cultural education and self-reflection. It is not medical, legal, or financial advice.
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