Researches on ostracism became popular in the 70s of last century, with the development of theories of belonging needs and self-esteem. It is typically defined as being ignored and excluded, and often occurs without excessive explanation or explicit negative attention. Workplace ostracism, which is usually conducted by supervisors or colleagues in the organizations, is one special example. After being ostracized, individuals’ fundamental needs (especially the belonging need) will be threatened, and then victims have to search for various ways, including behavioral changes, to compensate these thwarted needs. In other words, workplace ostracism is likely to influence organizational behaviors. The current study was to explore the relationships among workplace ostracism (both from supervisors and coworkers), employees’ in-role behaviors and extra-role behaviors (i.e., organizational citizenship behavior), and the mediating role of belonging need in aforesaid relationships, based on the William’s temporal need-threat model. In total, 247 employees collected from different organizations were sampled. To avoid the common method variance two waves of survey were administrated, using time-lagged design with one week in between. In the first wave, employees were asked to provide ratings of workplace ostracism (both from supervisors and coworkers) and some demographic information. In the second wave, the satisfaction of belonging needs and the level of both in-role and extra-role behaviors were asked. After investigated, the data collected in two waves were matched, input into computer and analyzed by software of SPSS 16.0 Hierarchical Regression Modeling (HRM) was employed to analyze the data. Results indicated that: workplace ostracism (both from supervisors and coworkers) could negatively predict employees’ in-role behaviors and extra-role behaviors, but these relationships would be mediated by belonging need, namely, workplace ostracism could affect employees’ belonging need, then their behavioral performance would be impaired at last. Workplace ostracism is a negative phenomenon that can not be ignored. These findings not only examined the relationships among workplace ostracism, belonging needs, in-role and extra-role behaviors, but also attracted attentions of domestic scholars to workplace ostracism which is a hot area of occupational health psychology. Future researchers can explore the influence of ostracism on employees’ attitude, behavior and health integratedly, and the mediating effect of other fundamental needs, i.e., self-esteem, meaningful existence, and control need. It is also interesting to understand the response of victims after being ostracized for a long timefrom dynamic perspective.Besides theoretical contributions, the present findings hada lot of important practical implications. For example, they offered some suggestions of preventing workplace ostracismfor organization managers and how to reduce its influence for victims through satisfying their belonging need.