In Chinese astrology, the concepts of "三合" (San He) and "六合" (Liu He) are integral to understanding the relationships between the different signs of the Chinese zodiac. These concepts are used to identify compatibility and harmony between the signs, based on traditional beliefs about the flow of Qi (energy) and the fundamental principles of Yin and Yang.
三合 (San He) - The Three Harmonies
The "三合" (San He), or Three Harmonies, refers to the grouping of the twelve Chinese zodiac animals into four compatible triads. Each triad consists of three animals that are believed to share similar temperaments, values, and outlooks on life, fostering harmony and beneficial relations among them.
San He is often considered in contexts where group dynamics are important, such as family relationships, friendships, and work teams. It suggests that members of a San He group will support and enhance each other's fortunes and well-being.
The four triads of the San He are:
1. Rat🐭, Dragon🐲, and Monkey🐵:
These signs are known for their intelligence, dynamism, and ambition. They are action-oriented and often successful in their endeavors through strategic planning and mutual support.
2. Ox🐂, Snake🐍, and Rooster🐓:
Characterised by their persistence, wisdom, and attention to detail, this group values tradition and are known for their methodical approach to achieving their goals.
3. Tiger🐅, Horse🐎, and Dog🐕:
This triad is celebrated for its members' bravery, independence, and sense of justice. They share a passionate and straightforward approach to life.
4. Rabbit🐇, Sheep (Goat)🐐, and Pig🐷:
Known for their compassion, creativity, and sensitivity, these signs prioritise harmony and are adept at fostering peaceful and supportive environments.
六合 (Liu He) - The Six Harmonies
The "六合" (Liu He), or Six Harmonies, focuses on one-on-one relationships, pairing the twelve zodiac signs into six pairs. Each pair is thought to have a direct and profound connection, often viewed as the most compatible or harmonious matches within the zodiac.
It is particularly relevant in the context of close personal relationships, such as romantic partnerships, deep friendships, or close business partnerships. It indicates a strong, one-on-one connection where two individuals complement and balance each other perfectly.
The six harmonious pairs are:


These concepts of San He and Liu He are deeply ingrained in Chinese culture, influencing people's decisions in relationships, business partnerships, and even in choosing auspicious dates for important events. They reflect the Chinese belief in the interconnectedness of all things and the importance of living in harmony with the natural world.
Differences:
- Structure and Grouping: San He is about triadic relationships (groups of three), while Liu He focuses on dyadic relationships (pairs).
- Type of Harmony: San He promotes a collective harmony among three signs, whereas Liu He emphasises a deep, one-on-one compatibility.
- Context of Use: San He can be applied to broader group dynamics, enhancing collective well-being and success, while Liu He is more focused on the strength and depth of individual relationships.
Hence, while both concepts aim to enhance understanding and harmony among the Chinese zodiac signs, San He looks at how groups of three signs interact and support each other, and Liu He zeroes in on the intimate and complementary nature of pairs of signs. Each concept provides a unique lens through which to view relationships and compatibility in Chinese astrology.