Emile Durkheim wrote Social Division of Labor while western countries transformed to modern society from premodern society. His thought, to some extent, can be a reference for China in the social transition today. Social solidarity, together with its two types, is the main clue of the book. The book made a deep analysis of solidarity in terms of types, characteristics, historical transition, spiritual foundation, legal guarantee, and threatening elements, which showed Durkheim’s concerns about social unity and harmony, and will be of instructive significance to social transition and development of China.