Objective To explore the characteristics of clinical symptoms and serum brain-derived neurotrophic factor(BDNF)level between depressive patients with and without attempted suicide behavior.Methods Serum BDNF level in depressive patients with(n=36)and without(n=55)attempted suicide behavior were assayed by ELISA,the severity of depression was measured by Hamilton rating scale for depression(HAMD).Results HAMD24 total scores(t=3.632,P=0.000),cognitive disturbance(t=-2.339,P=0.019)and hopelessness factor scores(t=-2.812,P=0.005)in depressive patients with attempted suicide behavior were significantly higher than those in depressive patients without attempted suicide behavior.There were no significant differences of anxiety/somatization,body weight,diurnal variation,psychomotric inhibition and sleeping disturbance fator scores between two groups(P＞0.05).The serum BDNF level in depressive patients with attempted suicide behavior was significantly lower than that in depressive patients without attempted suicide behavior(t=-2.122,P=0.037).There was no significant difference of serum BDNF level between male and female patients(P＞0.05).Conclusion There were certain characteristics on clinical symptoms of depressive patients with attempted suicide behavior.The low serum BDNF level might play an important role in the risk of suicide in depressive patients.