Objective To explore the characteristics of family function in children and adolescents with major depressive disorde（r MDD） and suicide attemp（t SA）. Methods From January 2019 to January 2020， 66 children and adolescents aged from 11 to 18 years with MDD and SA were recruited from the outpatient department and inpatient department of West China Hospital of Sichuan University（ MDD with SA group） and 75 children and adolescents with MDD without SA（ MDD without SA group）. 70 healthy children were recruited from the society and schools by posting advertisements（ healthy control group）. The severity of depression was assessed by Beck Depression Inventory. Family general condition scale and Family Assessment Device（ FAD） scale were used to investigate general family function and the seven dimensions of family function. Multiple logistic regression was used to analyze the influencing factors of children and adolescents with MDD and SA. Results There was no significant difference in the score of Beck Depression Inventory between MDD with SA group and MDD without SA group［ 35.00（28.00，42.00） vs 34.0（27.00，41.00），Z=1.310，P=0.190］. Compared with the healthy control group， the results of MDD with SA group were as follows： the emotional response factor ［18.00（15.00，19.50） vs 15.00（13.00，17.00），Z=-4.741，P ＜ 0.01］， communication factor［ 25.00（22.50， 28.00） vs 21.00（19.00，23.00），Z=-5.310，P＜ 0.01］， role factor［ 31.00（28.00，34.00） vs 28.00（26.00），Z= -4.434，P ＜ 0.01］， emotional intervention factors［16.00（14.00，19.00） vs 13.00（12.00，15.00） score，Z= -4.426，P＜0.01］， behavior control factor［ 22.00（20.00，23.00） vs 20.00（18.00，22.00），Z=-3.451，P=0.002］， problem solving factor［ 15.00（12.00，17.00） vs 13.00（12.00，14.50），Z=-3.404，P ＜ 0.01］， general function factor［ 32.00（27.00，35.00） vs 25.00（23.00，28.00），Z=-5.337，P＜0.01］. High affective responsiveness score（ OR=1.150， 95%CI=1.036-1.278，P=0.009）， family disharmony（ OR=5.912， 95%CI=2.319-15.090， P＜0.01）， poor health status（ OR=6.360， 95%CI=1.964-20.594，P=0.002） and mother's education background （Bachelor degree or above）（ OR=5.392， 95%CI=1.539-18.900，P=0.008） were the related factors of SA in children and adolescents with MDD. Conclusions Children and adolescents with MDD and SA often have poor family function， which is related to MDD and SA.