The aim of this study was to test whether the association between belief in a just world (BJW) and Internet altruistic behavior (IAB) was mediated by gratitude and self-esteem in a sample of Chinese undergraduates. A total of 238 participants (aged from 18 to 25) completed a paper-and-pencil questionnaire which assessed their BJW, self-esteem, gratitude, and Internet altruistic behavior. Mplus 7.0 was used to conduct structural equation modeling to estimate direct and indirect effects. Path analysis showed that self-esteem and gratitude partial...