Objective To explore the effect of sex hormone levels on adolescent non-suicidal self-injury behavior(NSSI)and the correlation between sex hormone levels and Hamilton Depression Scale 24-item score(HAMD-24).Methods A total of 95 adolescent patients with DSM-5 NSSI were selected as the NSSI group.During the same period,78 healthy adolescents who underwent physical examination in hospital were selected as the CN group.The demographic data and the levels of follicle-stimulating hormone(FSH),luteinizing hormone(LH2),estradiol(E2),prolactin(PRL),progesterone(P)and testosterone(T)in each group were collected.The general data and the sex hormone level in peripheral blood of NSSI group and CN group were compared,and the correlation between sex hormone level in peripheral blood of monophasic depression and bipolar depression patients and HAMD-24 score was analyzed respectively.Results E2,PRL,P,and T showed significant difference between the NSSI group and the healthy control group(P<0.05),and there was no significant difference in sex hormone level in peripheral blood between monophasic depression group and bipolar depression group(P>0.05).There was a positive correlation between PRL level and weight factor of HAMD-24 score in the NSSI group.The level of E2 in peripheral blood of patients with monophasic depression was negatively correlated with diurnal variation of HAMD-24 score.Conclusion Changes in the incidence of adolescent NSSI and E2,PRL,P,T level has relationship.The increase of E2,PRL and P levels and the decrease of T level in peripheral blood may have an impact on NSSI in adolescents.