With the popularity of the Internet, the human communication becomes more social, online and virtual. The traditional offline communities gradually expand to online virtual communities. Sharing information in virtual communities like Micro-blog, Wechat, Douban and Zhihu has been a kind of lifestyle. What are the influences of people’s incentives to share information in virtual communities? The paper analyzes the question from the aspects of personal daily life, the relationships in virtual communities and the whole social culture. This study finds that on the micro level, sharing information in virtual communities help individuals to build self-identity and self-reproduction. On the medium level, the incentives come from the mutual beneficial mechanism. On the macro level, the spirit of sharing and participating in the age of Internet has encouraged people to engage in carnival in virtual communities.