Abstract: This article is an intellectual history study on the traditional family system. It is based on the relevant texts in Rituals (Yi Li) and Book of Rites (Li Ji) with a focus on a kinship system known as the Nine-Generation clan system (Jiuzu Zhi). As an ideal family structure of Confucianism, the Nine-Generation system is an essential part of the traditional patriarchal clan system in Chinese society. This study examines the fundamental basis and its construction principle and process of the Nine- Generation system from the perspective of Confucianism.
The Nine-Gen eration system starts at the centre of oneself and ends with a gradually extrapolated circle of kinship. The circle defines the scope of kinship that one has. In the Book of Rites:Funeral Dresses, it is said: "In counting the kindred (in mourning rituals), from the three closest generations it expands to the next closest five generations, and then from the five to the next nine. The mourning dressing codes and the period of mourning are gradually diminished as the generations ascend or descend outwards to the collateral branches, and eventually end beyond this point." This scripture is the key to understand the Nine-Generation and it reveals the core construction principle of the system, which is called "Diminishing Attachment of Kinship". Starting from oneself, one has affection for one's father, this affection is extended to one's immediate ancestors, and then to further distance ancestors. The same with the descent order from one's sons to grandsons and so on. In the process, the further out the circle, the more diminished affection for each other. Therefore, "Diminishing Attachment of Kinship" becomes the most important construction principle and it eventually forms the Nine-Generation kinship group linking great- great-grandfathers to great-great-grandsons.
The study points out the significance of the Nine-Generation in Confucianism, arguing that it is the institutionalized interpretation of the "father-son" cardinal relationship and the essential ethic principal of "filial piety" in Confucian humanism. In addition, the study also examines the relationship between the Nine-Generation system and the traditional patriarchal clan system, asserting that the former is the prerequisite for understanding the latter.

Key words: Nine-Generation, father-son, diminishing love of kinship