[Purpose/significance] Virtual communities have become the important platform where members share knowledge. [Method/process] This paper summarized the virtual community knowledge sharing from different theoretical perspectives, and reviewed the knowledge sharing from two different angles. [Result/conclusion] In the process of knowledge sharing, knowledge contribution and knowledge acquisition were two different ways of behavior, which was not the same as the continuous knowledge sharing in the virtual community. The virtual community should consider the different influence factors of knowledge contribution and knowledge acquisition, and promote the sustainable knowledge sharing. At last, this paper explores the problems in current research and predicts future research trends.