As popular media sites, social network sites(SNS) are becoming the main platform of human being’s communication. One of the most important SNS use behaviors is online self-disclosure, and it is also one important motivation for SNS use. Some studies have showed that online self-disclosure behaviors decrease one’s loneliness, but it’s still unclear how that happened. In this study,1038 middle school students and high school students were surveyed with questionnaires. The present study examined the association between different dimensions of self-disclosure and loneliness, especially the mediating role of online positive feedback and online bonding social capital. The results revealed that:(1) There is no significant difference between boys and girls in their disclosure amount and depth; but girls disclosed significantly more than boys, at the same time, girls disclosed more positive than boys. There is no significant difference between middle school students and high school students in disclosure amount and depth; but high school students disclosed significantly more extensively than middle school students, at the same time, high school students disclosed more positively than middle school students.(2) The self-disclosure amount, breadth, valence of teenagers could negatively predict loneliness, but the depth of self-disclosure positively predict loneliness.(3) The online positive feedback and online bonding social capital the teenagers got online could significantly negative predict loneliness.(4) The online positive feedback played partial mediation roles between online self-disclosure amount, breadth, valence,depth and loneliness,the maximum effect size emerged in the relationship between breadth and loneliness; the online bonding social capital played a partial mediation effect on self-disclosure amount, breadth, depth, valence, and the effect size was higher in the relationship between self-disclosure amount, depth.(5) Online positive feedback and online bonding social capital played sequential mediating roles between online self-disclosure amount, breadth, depth, valence and loneliness. |