Research Objectives Dysfunctional executive control is one of the core characters for the addiction, and it has important influence on the relapse and maintenance treatment for the heroin treatment patients(HTPs). The present study employs the event-related potentials (ERPs) technique to reveal the time course of information processing with high temporal resolution, and exam the altered function of conflict monitoring and conflict resolution processing among HTPs. Methods Seventeen HTPs (mean duration of heroin use(9.97±5.08)years with average abstinence (2.32±2.05)years) were chosen from Methadone Maintenance Treatment Clinic of No.2 People’s Hospital in Chongqing as HTPs group, and seventeen matched healthy adults were recruited from society as control group. All participants were conformed to the standards of the experiment, and performed a classic word-color Stroop task. The experimental materials contain two kinds of stimuli, the congruent stimuli were four color words whose meaning were congruent with the writing colors(eg, the word “red” written in red), and the incongruent stimuli were the same four color words whose meaning were incongruent with the writing colors(eg, the word “red” written in green). The experiment adopted mixed design of 2(condition types)×2(groups), and required the participants to response to the condition types by pressing the corresponding buttons. According to the experiment by the two response types of ERP average figures, the present study performed three factors of repeated measure of variance analysis (brain regions * condition types *groups) with nine electrode records sites, two within-subject factors were respectively brain regions [frontal areas(F3/Fz/F4), central areas(C3/Cz/C4) and parietal areas(P3/Pz/P4)], condition types (congruent/incongruent conditions), the between-subject factor was group types(HTPs /control). Results The results show that there are significant within-subjects Stroop interference effects, and find that ERP wave forms are more negative than the control group, and significant differences in N2 (270-320ms) and SP (650-800ms) for HTPs group. There are significant interaction effect between condition and group of frontal N2(p=.013) and central SP(p=.022), and N2 effect (p=.009) and SP effect(p=.045) are significant for the control rather than for HTPs group. Conclusions This study finds impaired conflict monitoring during the early stimulus conflict process and impaired conflict resolution during the late conflict response process for HTPs, and implies that the abnormal executive functions of HTPs may be resulted from the brain functional damage because of chronic heroin abuse.