ObjectiveTo investigate gender differences of factors (temperament, impulsivity, and polymorphism of COMT gene) for predicting the relapse of heroin by a 5-year follow up.MethodsImpulsivity, temperament, and character of 564 heroin dependent patients were evaluated by Barratt impulsiveness scale (BIS) and temperament and character inventory. The polymorphism of COMT gene rs4680 was detected by a DNA sequence detection system.ResultsAmong 564 heroin dependent patients, 500 patients were followed up for 5 years. 265 (53%) of them relapsed into heroin and 127 patients were male and 138 patients were female. Logistic regression analysis showed that the total score of BIS, methadone maintenance treatment, and duration of heroin use were factors for predicting the relapse of heroin according to 5 years of follow up. For females, the starting age of heroin use, alcohol dependent, methadone maintenance treatment, and score of self orientation were factors for predicting the relapse of heroin.ConclusionThe impulsivity, temperament, and polymorphism of COMT gene are relevant to the relapse of heroin. Gender differences exist for predicting the relapse of heroin by these factors.