Reciprocity and trust are the basic principles of human social exchanges. Using a sample of 972 managers in China, we examined the relationship between transformational and transactional leadership styles and job-related attitudes of employees, as well as the mediating effects of both reciprocity and trust on the above relationship based on social exchange theory. The main findings of structural equation modeling analyses were shown as follows. Firstly, transformational leadership not only affects organizational trust and commitment directly, but also motivates organizational trust of employees through the mediation of generalized and balanced reciprocity indirectly, and thus enhances organizational commitment and stay intention of employees. Secondly, transactional leadership indirectly affects organizational trust and commitment of employees through the mediation of reciprocity. Thirdly, generalized reciprocity has direct effects on organizational commitment of employees, whereas balanced reciprocity exerts its influences through affecting organizational trust of employees. Managerial suggestions are provided.