Abstract: Objective To study the protective effect of Antidotal Decoction of Coptis(ADC) on myocardial ischemia/reperfusion(I/R) injury and its mechanism. Methods A SD rat myocardial I/R injury model was established.Fifty-six SD male rats were randomly divided into sham operation group,myocardial I/R group,1% CMC-Na control group,and low dose ADC group,medium dose ADC group,high dose ADC group,and composite red sage root group.The rats were given drugs for successive 7 days.The myocardial I/R injury model was replicated 24h after the last drug administration.SOD activity,MDA level,and myocardial infarct area were measured 40min after reperfusion to judge the protective effect of ADC on myocardium.Myocardial tissue sample was taken to measure the nuclear transcription activity of NF-κB. Results Forty minutes after reperfusion,the SOD activity,MDA level and myocardial infarct area were obviously improved in experimental groups,the nuclear transcription activity of NF-κB was significantly lower in experimental groups than in control group. Conclusion ADC protects rats against myocardial I/R injury by inhibiting the activation of NF-κB.