Adopting a dynamic view of guanxi, we investigated how the closeness in Chinese coworker relationship changes as a function of interpersonal incidents, exploring factors such as the prior closeness level as well as the valence and job relevance of the incident. Two studies of PRC managers probed the content and dynamics of their coworker relationships. Results indicate that such relationships mix affective and instrumental ties. A key finding about changes is that the increase in closeness created by positive incidents was greater when the prior relationship was distant, and the decrease created by negative incidents was greater when the prior relationship was close. The implications of these findings for theory development and future guanxi research are discussed.