Social networking sites (SNSs), which provide abundant social comparison opportunities, are ubiquitous around the world, especially among adolescents. In China, Qzone stands out as the most popular SNS. Due to the opportunity it provides for meticulous self-presentation, SNS may give the impression that others are doing better, which is detrimental to individuals’ well-being. Based on social comparison theory, the current study aimed to investigate the association between Chinese adolescents’ SNS (Qzone) use and depression, as well as the mediating role of negative social comparison and the moderating role of self-esteem.

A total of 764 adolescents (aged 12–18 years, M = 14.23, SD = 1.75), who had an active Qzone account, were recruited voluntarily to complete questionnaires on Qzone use intensity, negative social comparison on Qzone, self-esteem, and depression.

More intense Qzone use was associated with higher level of negative social comparison on Qzone, which fully mediated the association between Qzone use and depression. Moreover, the mediating effect of negative social comparison on Qzone was moderated by self-esteem. The specific link between Qzone use and negative social comparison was weaker among adolescents with high self-esteem than those with low self-esteem.

As all the data in this study were self-reported and cross-sectional, causal associations cannot be identified. Additionally, the specific activities on SNS were not identified.

Negative social comparison may be a key factor and mechanism accounting for the positive association between SNS use and depression, while self-esteem could protect adolescents from the adverse outcome of SNS use.