【Purpose/significance】In recent years, scholars have studied the factors that influence knowledge sharing in virtual communities based on different theories. However, no review has systematically discussed the theories that most studies took and the research findings of corresponding variables’ influences.【Method/process】In this paper, we used literature research method to summarize existing empirical study of knowledge sharing in virtual communities, and identified four mostly used representative theories. Moreover, we analyzed the achievement of current research on knowledge sharing in virtual communities based on these four theories, and elaborated the influences of corresponding variables of those theories.【Result/conclusion】We constructed the comprehensive empirical research model of knowledge sharing in virtual communities as to four theories. The deficiencies of existing research and future research directions were finally concluded.