This paper includes enterprise social media into social network theory and social exchange theory to understand employees’ job performance by distinguishing employees’ network tie in organizations. Enterprise social media is rapidly implemented in the workplace as tools for communication among employees. It is critical issue that how they are accomplished in the organizations. First of all, we provide the various definition of enterprise social media and suggest the relative theories. Specifically, we conceptualize the network centrality among social network tie as closeness centrality and structural hole in both online and offline workplace. thus resulting in four distinct types. Secondly, we theorize that employees’ centrality in online and offline are complementary resources that interact to influence their job performance. because the one who has a large number of ties in both networks will be able to leverage the benefits and is less constrained in organization. Lastly, we consider the moderating effect of Leader-Member Exchange(LMX) between employees’ network ties and job performance. LMX refers to the different types of relationships that leaders developed among their subordinates, and as a boundary condition for the associated outcomes. To serve the purpose, we conducted an empirical study using the data of 133 employees in 21 team of companies. The results indicate that online and offline employees’ network ties enhance a job performance. And according to the interaction level, complementarity of online and offline and LMX have negative moderating effect on job performance. In conclusion, this study shows that we need consensus about the purpose and utilization level of enterprise social media in advance under the employees’ weak and strong tie mechanisms in the online and offline workplace environment.