Objective To explore the relevant factors of suicidal tendencies among inpatients with major depressive disorder. Methods A total of 1 160 patients with depressive disorder who were hospitalized in Beijing Anding Hospital affiliated to Capital Medical University from November 2017 to December 2018 were selected as subjects and divided into suicide group （n=431） and non-suicide group （n=729） according to suicidal tendencies （including suicidal ideation and attempted suicide）. The clinical characteristics of the two groups were compared， and the binary logistic regression analysis was used to explore the relevant factors of suicidal tendencies among inpatients with major depressive disorder. Results Univariate analysis showed that there were statistically significant differences between the two groups in terms of gender， impulsive personality， history of psychoactive substance dependence， family history of suicide， history of major mental trauma， and severity of depression （χ2 =5.841，33.806，5.869，5.585，5.499，33.311， respectively；P ＜ 0.05）. Binary Logistic regression analysis revealed that impulsive personality （OR=2.445， 95%CI：1.802-3.319）， history of psychoactive substance dependence （OR=2.254， 95%CI：1.038-4.894）， history of major mental trauma （OR=1.533， 95%CI：1.056-2.226）， and severity of depression （OR=2.754，95%CI：2.002-3.790） were the influencing factors for suicidal tendencies of inpatients with depressive disorders. Conclusions Impulsive personality， history of psychoactive substance dependence， history of major trauma， and major depressive symptoms may increase suicidal tendencies among inpatients with depressive disorders.