Abstract:To discover and understand the factors and mechanism which affect knowledge sharing intention has a strategic value for enterprises to gain a competitive advantage. So, in this paper, a game model is constructed based on the perspective of market competition structure. And then, it is analyzed about the influence of initial market capacity, market share and market capacity-added on knowledge sharing intention of knowledge-leading enterprise within the virtual alliance. The results show that: Firstly, the market competition structure has an important impact on knowledge sharing intention of knowledge-leading enterprise. Secondly, there is a relationship with inversed “U” shape between initial market capacity and knowledge sharing intention of knowledge-leading enterprise, and there is a positive correlation between market capacity-added and knowledge sharing intention of knowledge-leading enterprise. Thirdly, if a virtual alliance can form effective regulations to keep the competitive structure of market stable, it will effectively enhance the knowledge sharing intention of knowledge-leading enterprise. This paper provides a new perspective and thought to promote and improve the knowledge sharing among enterprises.