The previous research about the influence of social capital on knowledge sharing and intellectual capital has been less exploited so far, while the characteristics and components of social and intellectual capital and the process and strategies of knowledge management have received much more attention. In order to look into the effect of organizational structure, cognition and trust of social capital on knowledge sharing and to understand whether knowledge sharing plays as an mediator in the influence of utilizing social capital on intellectual capital, this study conducted Linear Structual Relation (LISREL) to test the hypotheses with 269 questionnaires of domestic listing and over-the-counter companies. The results shown that when firms with abundant social capital seize the advantaged structural capital of network tie with trust and cognition sharing, not only would omni-bearing learning and frequency of knowledge interflow be motivated, but also would willingness as well as ability of knowledge sharing be increased. In addition, knowledge expansion would accelerate due to reciprocal social capital, which drives the accumulation of intellectual capital such as human capital, structural capital and customer capital. Accordingly, enterprises are suggested to construct inter-relationship, motivate trust and cooperation, actively foster social capital, and simultaneously leverage social capital to stimulate knowledge interflow and further accumulate intellectual capital to promote business value.