Abstract: The long existing phenomenon of "Inbreeding" of the universities has its historical and cultural causes, and contradicts the task of innovating knowledge and talents shouldered by today's colleges. The vitality of the innovation of knowledge and system will be affected if the colleges in China fail to control or put an end to this phenomenon. This article analyzes the social and cultural causes of the phenomenon of "Inbreeding" of the Chinese colleges, discusses its harms, and presents some advice on the reform of the personnel policy of the colleges.