The rapid change in technology and society requires employees to continually manage change in their organizational environment. Employees with proactive personality are more willing to seek out opportunities, take initiatives, and promote meaningful change. Therefore, proactive personality has been found to play an important role in driving career success of individuals and the competitive advantage of their organizations. However, some studies suggested that the effect of proactive personality might be exaggerated or misinterpreted. Whether proactive personality will lead to positive work outcomes may depend on other factors. The objective of this study was to explore the mechanism how proactive personality take effect on work related behaviors. This study applied a longitudinal moderated mediation model to investigate the mediation role of proactive socialization behavior (PSB) in the relationship between proactive personality and organizational citizenship behavior (OCB) and the relationship between proactive personality and task performance, and examined whether the mediation effect of PSB would be moderated by individuals’ political skills. A total of 243 employees participated in this study. A longitudinal design was employed in data collection procedure with the interval of two months. Data of demographic information, proactive personality, and political skill were collected at Time 1; data of PSB, OCB and task performance were collected at Time 2. All data were collected by self-rated questionnaires, except that OCB and task performance were assessed by the direct leaders of the participants. The results showed that: (1) proactive personality was positively associated with PSB; (2) PSB was positively associated with OCB and task performance; (3) PSB mediated the influence of proactive personality on OCB and task performance; (4a) political skill moderated the relationship between proactive personality and PSB that the relationship was stronger when participants had higher political skills; (4b) the mediation effect of PSB on the relationship between proactive personality and OCB and the relationship between proactive personality and task performance was moderated by political skill that the mediation effect was stronger when participants showed higher political skills. The results revealed the mediation role of PSB in the influence of proactive personality on OCB and task performance, which provided a possible explanation how proactive personality affected work related behaviors. The moderation effect of political skills suggested that proactive personality is more likely to lead to positive work outcomes when employees had higher political skills. The findings of this study enriched the literature of proactive personality and provided support for future exploration of conditions under which proactive personality would be beneficial to individuals and organizations. Practical implication included but not limited to the following two items. On one hand, given the positive effect of proactive personality on work performance, organizations may consider including proactive personality assessment in personnel selection process. On the other hand, considering the conditional effect, political skill enhancement training should be provided to all the staff in organization to accelerate their organizational socialization and achieve mutual development of both employee and organization.