Common Concepts
What Are the Heavenly Stems (Tian Gan)?
Also called: Tian Gan, Tiangan, Ten Heavenly Stems
Plain Explanation
The Heavenly Stems are ten characters traditionally used to mark sequence and time: Jia (甲), Yi (乙), Bing (丙), Ding (丁), Wu (戊), Ji (己), Geng (庚), Xin (辛), Ren (壬), and Gui (癸). In the Four Pillars of BaZi, a Stem is written in the upper position of each pillar.
Example
Each of the Four Pillars has a Heavenly Stem in its upper position. For example, Jia (甲) is yang Wood and Yi (乙) is yin Wood. The element and polarity correspondences for all ten Stems are listed below.
| Name | Element | Yin or yang |
|---|---|---|
| Jia (甲) | Wood | Yang |
| Yi (乙) | Wood | Yin |
| Bing (丙) | Fire | Yang |
| Ding (丁) | Fire | Yin |
| Wu (戊) | Earth | Yang |
| Ji (己) | Earth | Yin |
| Geng (庚) | Metal | Yang |
| Xin (辛) | Metal | Yin |
| Ren (壬) | Water | Yang |
| Gui (癸) | Water | Yin |
What It Is Used For
Heavenly Stems pair with Earthly Branches to record the year, month, day, and hour. In BaZi, they also identify the Day Master, while their elements and yin-yang polarities determine Ten-God relationships.
Common Misunderstandings
The Heavenly Stems are not ten personality labels
A Stem’s element and yin-yang polarity are classifications. A person’s character cannot be inferred from a Heavenly Stem alone.
Related Concepts
Updated 2026-10-16 · Editorial Policy