This study deals with a competitive knowledge network (CKN) where participants desire to pass their personally important exams, and henceforth want to contribute and seek knowledge about exam-related issues they need to solve. Besides, CKN members are basically competing with each other since they all aim to pass the same exams. Therefore, from the contributor`s perspective, if the advisor fears that his/her advice can be detrimental to his or her own benefits, knowledge sharing (KS) intention within the CKN may be hindered by their expectation of competitive advantage. However, few studies were done about the effects of such fear and a sense of competition on KS continuance intention in the context of CKN. In this sense, our study aims to elucidate the effects of competition and fear on KS continuance intention in a mobile CKN. By using 296 valid questionnaires, we obtained very meaningful conclusions such that competition is a driving force rather than an obstacle to KS among CKN members, and fear also enhances members’ sustainable KS intention.