knowledge sharing (KS) could add to increment for knowledge of its organization. But there are so many of barriers in the KS process, because of so many influencing factors which include individuals & knowledge characteristic, & organization, and etc. So Pareto Optimum achievement should be used for how to improve the KS performance under positive motivation. Conceptual model of the knowledge sharing is put forward based on knowledge sharing mechanism researched by analyzing the drive-force of the knowledge sharing deeply & utilizing the uncompleted information dynamic repetition game theory, which gives more theory foundation to design Optimum mechanism for KS.