The research that has been done to date on marriage customs during the pre-Qin 先秦 period forms an enormous volume of literature;however, no standards of textual criticism concerning the one of the most frequently quoted source materials on the subject, the Zuo-Zhuan 左伝, exist to date. In the present article, the author applies Hirase Takao's content outline and "implicit" structural theory to the items in the Zuo-Zhuan concerning marriage, and investigates the geneologies of the major kingdoms. As a result of this analysis, the author shows that the work refutes the spouses and descendents of the Jiang 妾 family, a representative family of the Qi 斉 dynasty, showing a tendency towards breaks in lines of descent. Here, a "form" other than the form discovered by the Hirase can be indentified for the Zuo-Zhuan, in which the Lu 魯 and Jin 晋 Periud aristocrats, the San-Huan 三桓 and Jin period Han 韓, Wei 魏 and Zhao 趙, and the Jin period Han and Qi period Chen 陳 all correspond, forming a triplex structure. The Zuo-Zhuan contains items on marriage that degrades all families other than the Han, in order to legitimize the Han kings of the Warring States period as descendents of Han Xuan Zi 韓宣子. In addition, the marital evaluations contained in the relatively new tales and dialogues contained in the Zuo-Zhuan negate matrilineal lines deriving from the Ji 姫 name. Also, in pre-Qin times there are regions in which matrilineal blood lines were emphasized, as indicated in the extant bronze inscriptions and bamboo documents from the period. What this means is that checks existed against any attempt to legitimize one's authority based on a marital affiliation with a women with a Ji name, leading one to believe that the Zuo-Zhuan was ideologically opposed to the involvement of women in politics. The Zuo-Zhuan was thus a very politically influenced work utilized to legitimeze the power structure to which its editors advocated. On the contrary, other works of the Qi period, the Chun-Qiu 春秋 and Gong Yang Zhuan 公羊伝, for example, took positions concerning marriage contrary to the Zuo-Zhuan. It was in this way that the various kingdoms of the Warring States period attempted to legimitize their authority by either utilizing marital relations from the past or refuting those of their political rivals, a process within which views about marriage were gradually institutionalized and traditionalized for future generations. Therefore, it is important to keep in mind the fact that the concept of marriage went through a transition half way through the period.