Abstract： The model of firm’s internationalization process based on social capital and knowledge innovation describes such an infinite circulatory logical process, that is, “international social capital-internationalization knowledge innovation-enterprise’s internalization behavior”. Using internationalization knowledge innovation as the intermediate variable, and the empirical research frame of the relationship between international social capital and firm’s internationalization features is constructed: international social capital has a notable positive influence on the internationalization knowledge innovation, in the meantime, internationalization knowledge innovation has a notable positive effect on the corporation’s internationalization features, and internationalization knowledge innovation plays a complete intermediate role in the relationship between international social capital and firm’s internationalization features. In order to make enterprise’ internationalization sustainable growth, great importance should be attached to the internationalization knowledge innovation, and the specific strategy is to strengthen the cultivation of international social capital.