Objective To investigate the effects of selective serotonin reuptake inhibitors（SSRIs） on social cognition in patients with major depressive disorders（ MDD）. Methods A total of 60 patients who met the Diagnostic and Statistical Manual of Mental Disorders-5 diagnostic criteria for MDD were allocated to a SSRI treatment group（ SSRITG， n=30） and a TCA treatment group（ TCATG， n=30）. The emotion intensity recognition task（ EIRT） and the interpersonal perception task-15（ IPT-15） were measured at baseline and then after 4 and 12 weeks of treatment with SSRIs or TCAs. The differences of IPT-15 scores and EIRT scores between research groups and control group were compared. Results Both SSRIs and TCAs decreased the Hamilton Depression Scale（ HAMD） scores. At baseline， the total scores and factor scores of the IPT-15 and EIRT were significantly lower in the SSRITG and TCATG than those of the controls. A repeated measures analysis of variance revealed a significant main effect of time period（ baseline， 4 weeks， and 12 weeks） and significant interactions for time period × group（ SSRITG and TCATG）. A multivariate analysis of variance showed no significant differences between the SSRITG and TCATG on IPT-15 scores and EIRT scores at the end of the 4th week， but there were significant differences between these two groups at the end of the 12th week. The score of the SSRIs was significantly higher than the TCAs group. Conclusions MDD patients have impairments in social cognitive function， which might be improved by SSRIs.