Objective:To study the effect of Huanglian Jiedu Tang（HJT） in the reversal effect of drug resistance in Escherichia coli.Method: E.coli with extended-spectrum β-lactamase is screened by disc diffusion method.The minimum inhibitory concentration of HJT was determined.The extended-spectrum β-lactamase enzyme E.coli was cultured with a HJT concentration lower than the minimum inhibitory concentration.The cultivation duration and optimal concentration for reversal effect were selected

and the reversal rate was determined.Result: Minimum inhibitory concentration of HJT to the E.coli ATCC8099 was 0.6 g · L-1.The cultivation duration was 30 h and the optimal concentration for reversal effect was 0.3 g · L-1.The reversal rate of ampicillin was 60.0%.The reversal rate of ceftazidime was 66.7%.The reversal rate of cefmetazole was 75.0%.The reversal rate of ceftriaxone was 66.7%.Conclusion: The effect of HJT for reversal drug resistance in E.coli is defined.It is a way to reverse drug resistance in E.coli.