To explore childhood trauma, family functioning, and social support related to attempted suicide in college students with depression. Methods: A total of 156 college students with depressive disorder were recruited and divided into the attempted suicide group (n=78) and non-attempted suicide group (n= 78) according to previous suicidal behavior. The two groups were evaluated with the Childhood Trauma Questionnaire (CTQ), Family Assessment Device (FAD), and Social Support Rating Scale (SSRS). Results: Compared with the non-attempted suicide group, the attempted suicide group had higher scores of emotional abuse (P<0.001), emotional neglect (P=0.001), sexual abuse (P=0.002), physical abuse (P<0.001), and physical neglect (P=0.001) and a higher total score (P<0.001); role (P=0.039), emotional intervention (P=0.023), total family function (P=0.010), and total (P=0.018) scores were higher; the subjective support (P=0.007), support utilization rate (P=0.005), and total (P=0.011) scores were higher. Emotional abuse, sexual abuse, and support utilization are independent risk and protective factors for suicidal behavior. Conclusion: College students with attempted suicide have more serious childhood trauma, worse family functioning, and less social support.