With the development of economy, increase of cultural exchanges and changes of people's ideology in China, the number of female sex workers (FSWs) increased rapidly under the influence of various social factors. The diverse motivations for women engaging in commercial sex have been observed. Foreign researchers have conducted some surveys of factors associated with female commercial sex, while few such studies were conducted among FSWs in China. This paper summarizes the progress in the research of reasons for women engaging in commercial sex both at home and abroad to provide evidence for future study.