Introduction
Every Chinese date — and every BaZi chart — is written with two overlapping cycles of characters. The Ten Heavenly Stems (天干) and the Twelve Earthly Branches (地支) pair up to name years, months, days, and hours. Learn these twenty-two characters and the whole system opens up.
The Ten Heavenly Stems
The stems are ten characters, each tied to one of the Five Elements and a yin or yang polarity:
- Wood — Jia (甲, yang), Yi (乙, yin)
- Fire — Bing (丙, yang), Ding (丁, yin)
- Earth — Wu (戊, yang), Ji (己, yin)
- Metal — Geng (庚, yang), Xin (辛, yin)
- Water — Ren (壬, yang), Gui (癸, yin)
In a chart, the stems are read as the outward, visible energy — the "what's happening" layer.
The Twelve Earthly Branches
The branches are twelve characters, each also carrying an element — and each paired with a zodiac animal:
- Zi (子, Water, Rat) · Chou (丑, Earth, Ox) · Yin (寅, Wood, Tiger)
- Mao (卯, Wood, Rabbit) · Chen (辰, Earth, Dragon) · Si (巳, Fire, Snake)
- Wu (午, Fire, Horse) · Wei (未, Earth, Goat) · Shen (申, Metal, Monkey)
- You (酉, Metal, Rooster) · Xu (戌, Earth, Dog) · Hai (亥, Water, Pig)
Branches are read as the hidden, internal layer — the deeper context under each stem. This is why the zodiac year chart works: your zodiac sign is simply the Earthly Branch of your birth year.
How They Combine: The 60-Year Cycle
One stem and one branch pair up to name a year. Because 10 and 12 are not multiples, the pairing cycles through 60 unique combinations before repeating — the sexagenary cycle that runs the Chinese calendar.
The same pairing also marks the day pillar and the hour pillar in a chart, which is how a birth time becomes four pairs of characters: year, month, day, and hour.
Why This Matters for BaZi
- Each pillar's stem and branch bring two elements into the chart.
- Branches interact — combinations and clashes between branches shape relationships.
- The hour branch, for example, tells you the animal of your birth hour, adding depth beyond the year sign.
With the stems and branches in hand, the Ten Gods and the patterns suddenly have characters to work with.
Frequently Asked Questions
What are the Ten Heavenly Stems?
They are the ten cyclical characters — Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren, Gui — each linked to an element and a yin or yang polarity. They mark the yearly and daily stems in a BaZi chart.
What are the Twelve Earthly Branches?
They are the twelve characters — Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, Hai — that pair with the zodiac animals and carry the Earth element of each pillar in a BaZi chart.
What is the 60-year cycle?
A stem and a branch pair up to name each year. Since 10 and 12 share a least common multiple of 60, the same combination returns every 60 years — this is the sexagenary cycle that the Chinese calendar runs on.
Are stems and branches the same as the zodiac?
They are related but not identical. Each Earthly Branch corresponds to one zodiac animal (Zi = Rat, Chou = Ox, and so on), but the branches also carry elements, directions, and seasonal meanings beyond the animal label.
Why do I need to know them for BaZi?
Every pillar in a BaZi chart is one stem plus one branch. Without recognizing the stems and branches, you cannot see the elements, the combinations, or the clashes that the whole reading is built on.
Conclusion
The stems and branches are the alphabet of Chinese metaphysics — small, fixed, and everywhere. Master the twenty-two characters and every chart, calendar, and zodiac system starts to feel familiar.
This article is for entertainment, cultural exploration and self-reflection purposes only. It is not medical, legal, financial, or investment advice.