The aim of the present study was to examine the mediating effect of self-concordance on the relationship between internet altruistic behaviour (IAB) and subjective wellbeing (SWB). A total of 356 Chinese university students (159 males and 197 females) participated, using the questionnaires in the Internet Altruistic Behavior Scale (IABS), the Self-Concordance Scale (SCS) and the General Well-Being Schedule (GWBS). Correlation results indicated that IAB was positively correlated with self-concordance and SWB. The hierarchical regression analyses indicated that both IAB and self-concordance positively affect SWB. Moreover, IAB affected SWB indirectly via self-concordance, which confirmed self-concordance partially mediated the relationship between IAB and SWB. These findings extend the previous research on the association between altruism and SWB.