The article reviews summarily the development of the official collections and private collections in ancient China, and analyzes their characteristics and shortcomings. The official collections and private collections were intimately related and influenced by each other. An example is given that Emperor Qianlong of Qing Dynasty paid close attention to the private collections, and took care to encourage and utilize them. Moreover, the authors affirm the private collectors' contribution to ancient books in the fields of conservation, communication, perfection, production and donation to the government. The article points out particularly that the cyclical character of the official collections was very obvious because they were gathered and scattered quickly and alternately. Whereas the continuity of private collections was better. The abundant document resources derive from the folk.