With the development of internet technology, professional virtual community (PVC) is becoming the valuable external knowledge source for graduate students. Students search information and knowledge in specific domain, share research experiences and weave their social network in these professional virtual communities (PVCs). How to use PVC to increase graduate students’ creativity should be an important researching issue. Although students’ online behaviors have got researchers’ attention, students’ PVC behaviors and their impacts on creativity keeps less comprehensively understood. The empirically analysis of totally 930 graduate students in this study turns out that graduate students’ PVC behaviors include 17 categories which then are clustered into three dimensions: Knowledge & Networking Behavior, Behave Manner and Interactivity. To test their impacts on graduate students’ creativity, the regression results demonstrate that after controlling students’ intrinsic motivation and creative self-efficacy, Knowledge & Network Behavior and Behavior Manner both significantly predict students’ creativity. However Interactivity does not affect students’ creativity. Implications and future research are discussed.