Commonality and personality are two perspectives on a thing. This paper makes a comparative study on the legal definition of public archives in the laws and regulations of overseas countries and regions, sums up their common experiences in expressing the legal definition of public archives, and analyzes their individualized practices in defining the formation of public archives, generic concept, ownership to legislative orientation and so on, from which some enlightenment can be drawn. Firstly,the definition of China's archival legal definition must be based on China's basic national conditions, social development and the background of the times. Secondly, it must clarify the formation and formation process of public archives. Thirdly, it must standardize the concept of public archives and its extension. The fourth is to clarify the corresponding concept of public archives in legislation, the fifth is to attach importance to the positioning of the archives of public archives.Finally, a supplementary explanation on the legal definition of public archives should be done.It is of reference for the academic circles to deepen the study of public archives and for legislators to formulate or revise the legal definition of public archives.