Objective To establish a multidrug resistance cell line of human bladder carcinoma and study the mechanism of multidrug resistance.Methods Human bladder carcinoma cell line T24 was induced to multidrug resistance cell line T24/ADM by intermittent administration of high dose ADM.The multidrug resistance was detected with MTT assay.The difference expressions of mdr-1 gene-coded P-glyeo protein(P-gp),multidrug resistance-associated protein(MRP),and LRP were examined with RT-PCR and Western blot.Results An adriamycin-resistant cell line T24/ADM was successfully established.It was cross resistant to many other chemotherapeutic agents,such as ADM,VCR and VP-16.The expression of P-GP, MRP and LRP were higher in multidrug resistance cell line than in parent line ADM.Conclusion T24/ADM was a model with multidrug resistance and the level of MDR mRNA expression were higher in T24/ADM than that in T24.