Abstract The purpose of this dissertation is to investigate and compare the effects of coworkers¡¦ relational demographic similarities and guanxi base on coworkers¡¦ helping behavior. Moreover, the mediation mechanisms of social liking between coworkers¡¦ relational demographic similarities and helping behavior, and guanxi obligation between coworkers¡¦ guanxi base and helping behavior were examined. Furthermore, the moderation effect of interdependent self on the relationship between relational demographic similarities and helping behavior, and the moderation effect of individual traditionality on the relationship between guanxi base and helping behavior were examined. There were three studies in this dissertation, and the data were collected by scenario experimental design combined with questionnaire survey. The subjects were working employees sampled from different industries. Results showed that both coworkers¡¦ relational demographic similarities and guanxi base have significant effects on the interpersonal-related helping behavior, but not on work-related helping behavior. Moreover, the mediation effects of social liking towards coworker, and guanxi obligation were significant in both study 1 and study 2. The moderation effect was not significant in study 1, but was significant in study 2. The individual traditionality moderated the relationship of guanxi base and guanxi obligation. The results of study 3 showed that coworkers with guanxi base have stronger effect on both interpersonal-related and work-related coworkers¡¦ helping behavior than coworkers with relational demographic similarities. The results were discussed and the limitations and suggestions for future research were proposed.