Nowadays, organizations are experiencing revolutionary change due to the advent of Enterprise 2.0 or enterprise usage of social networking tools. Practitioners and researchers are in their early stages experimenting with social media in organizational contexts. The central concern is how the enterprise usage of social media could be converted into the improved organizational performance. Organizational learning has long been considered as one of the measures of organizational performance. In this paper, we would like to understand how the enterprise social media could foster knowledge management processes and further influence the organizational learning. Theories from sociology and strategic management were used to build the hypotheses in the research model. An online survey was conducted to empirically test the model. Our study results show that Enterprise Social Networking Systems usage directly and indirectly influence organizational learning; and knowledge management processes (knowledge creation and sharing) mediate the path between Enterprise Social Networking Systems usage and organizational learning. The results give implications for both practitioners and scholars who are interested in further studies on organizational social media research.