Abstract: As a burgeoning platform for knowledge sharing, community question answering (CQA) is capable of satisfying personalized information needs for individuals, with its distinct type of interactions among users and openness.This paper reviewed the researches and applications of CQA. We systemically described the research topics in CQA,such as user behavior analysis, content quality detection, question searching etc, and the application of CQA in other forms of social media. Finally, we discussed some issues for further study. The discussions in this paper are beneficial to enrich and expand researches in CQA.

Key words: Community question answering, User behavior, Content quality detection, Question search