Objective To investigate the effect of drug dependence severity on the relationship between impulsivity and craving.Methods 36 abstiuent drug-dependent individuals were recruited in the study.The participants were divided into the heavy depeudence group (HDG) or the low dependence group (LDG) according to the scores of Addiction Severity Index (ASI).The Barratt Impulsiveness Scale (BIS-11) and classical Stroop task were used to measure the trait impulsivity and state impulsivity.Block designed cue-induced craving paradigm was presented to measure cue-elicited craving.Results For the HDG,a significant positive correlation was found between trait impulsivity (the mean value of BIS-11-CI scale was (39.03± 16.50)) or state impulsivity (the difference of reaction time between congruent and incongruent situation was (87.77±36.95)ms)and cue-elicited craving (0.83± 1.91)(r=0.487,0.500,P＜0.05).However,for the LDG subjects,the impulsivity was not found significantly correlated with the cue-elicited craving(r=-0.261,0.081,P＞0.05).Conclusion The addiction severity influences the relationship between impulsivity and craving,and impulsivity can only be used as a predictor of relapse in HDG.The findings suggest that the drug may influence the shared brain mechanism between impulsivity and craving.