Abstract:Upon on the previous studies on the relationship between social networks and tacit knowledge sharing, scholars draw three conclusions: positive prediction, negative prediction, or irrelevancy. However, these three conclusions make people question whether there is a causal relationship between them, and make no sense to know how the organization promotes sharing the tacit knowledge. This study intends to prove the causal relationship between social networks and the sharing effect of tacit knowledge through empirical studies, and to test the effectiveness of groups training on social networks skills to improve the marketers’ social network quality by two methods: questionnaire survey and intervened experiment. Results indicate that there is a causal relationship between social networks and the effect of tacit knowledge sharing, and group training on networks skills is an effective way to improve the quality of social networks of insurance marketers.