Abstract: The law of Fa Jing ( 《法经》 ) was enacted by Li Kui, then Shang Yang made the Code of Qin in the foundation of it when he was prime minister of Qin state. Xiao He enacted the Code of Nine Chapters ( 《九章律 》 ) by adding three articles to the law of Fa Jing in beginning of Westen Han Dynasty. During the period of Wei and Westen Jin Dynasty, both the Code of Wei and the Code of Taishi were made by adding articles to The Code of Nine Chapters taken as the blueprint of legislaion. In fact, the genealogy of the evolution of the ancient legal code mentioned above is not real, but was fabricated by Liu Shao、Zang Rong Xu、Wei Shou and the historians who writen the Jin Shu Criminal Law Annals in Tang Dynasty. As for the reason why they fabricated this genealogy, it may attribute to the influence of Confucianism, Taoism and Buddhism in the Wei, Jin and Southern and Northern Dynasties. It was a deliberate historical writing, which could not be treated with faith in history.