Social networking sites afford substantial affective self-expression and hybrid social connections. In this study, we collected 185 Facebook users' egocentric social network data and analyzed the words of positive emotion and negative emotion in their past status updates. Preliminary results reveal that sharing emotion on Facebook is associated with their social network size and density, and this association is moderated by the individual motivation for relationship management. We also found a decreasing trend of emotion sharing with longer usage of Facebook. Follow-up studies and implications are discussed.