Nowadays, millions of people around the world use social networking sites to express everyday thoughts and feelings. Many researchers have tried to make use of social media to study users’ online behaviors and psychological states. However, previous studies show mixed results about whether self-generated contents on Facebook reflect users’ subjective well-being (SWB). This study analyzed Facebook status updates to determine the extent to which users’ emotional expression predicted their SWB-specifically their self-reported satisfaction with life. It was found that positive emotional expressions on Facebook did not correlate with life satisfaction, whereas negative emotional expressions within the past 9-10 months (but not beyond) were significantly related to life satisfaction. These findings suggest that both the type of emotional expressions and the time frame of status updates determine whether emotional expressions in Facebook status updates can effectively reflect users’ SWB. The findings shed light on the characteristics of online social media and improve the understanding of how user-generated contents reflect users’ psychological states.