目的　探讨 5种多药耐药 (MDR)基因在肝癌组织中的表达 ,建立MDR的基因诊断标准。方法　用逆转录PCR、流式细胞术检测肝癌组织中 5种MDR基因mRNA和蛋白质的表达 ,用MTT法检测抗癌药物对肝癌原代细胞的IC50 值。结果　肝癌耐药涉及mdr1、MRP、LRP、GSTP1和TopoⅡα基因。mdr1mRNA≥ 0 5、MRPmRNA≥ 0 6、LRPmRNA≥ 0 8、GSTP1mRNA≥ 0 7和TopoⅡαmRNA≤ 0 4为耐药联合诊断标准 ,符合率为 98 0 0 %。结论　多重MDR是肝癌耐药的主要形式。用逆转录PCR方法联合检测 5种MDR基因mRNA表达在肝癌化疗敏感性预测中具有必要性和可行性。 Objective To investigate the expression of five multidrug resistance (MDR) genes in hepatocellular carcinoma and establish the diagnostic criteria for MDR genes. Methods Reverse transcription PCR and flow cytometry were used to detect the mRNA and protein expression of five MDR genes in HCC tissues. The IC50 values ​​of anticancer drugs against primary HCC cells were detected by MTT assay. Results The drug resistance of liver cancer involved mdr1, MRP, LRP, GSTP1 and TopoIIα genes. Mdr1 mRNA ≥ 05, MRP mRNA ≥ 06, LRP mRNA ≥ 0, GSTP1 mRNA ≥ 0.7, and TopoIIα mRNA ≤ 0 4 were combined diagnostic criteria for drug resistance with a coincidence rate of 98%. Conclusion Multiple MDR is the main form of drug resistance in liver cancer. It is necessary and feasible to jointly detect the mRNA expression of five kinds of MDR genes in the sensitivity prediction of hepatocellular carcinoma using reverse transcription PCR.