Public security, traffic management and service for the people are the three major functions of policing. To assure the quality of police service, which is contingent on the people who render the service, has become the core of policing. This study aims to investigate the relationship between work values and service-oriented organizational citizenship behaviors with Taiwan Police College's students as the research sample. The mediating effects of psychological contract and professional commitment are also explored in this study. It is found that work values have a positive effect on individuals' professional commitment and psychological contract. It is also found that psychological contract and professional commitment have positive effects on service-oriented organizational citizenship behaviors. Besides, work values are found to have a positive effect on service-oriented organizational citizenship behaviors through the mediation of psychological contract and professional commitment. Suggestions and recommendations for future research are thus discussed.