Abstract: Objective To study the role of PKC in multidrug resistance of bladder carcinoma.Methods Takai method was followed to measure the activity of PKC in bladder tumor tissues and normal tissues around the tumor.And RT-PCR method was used to measure the mRNA expression of P-gp and MRP in both region as PKC.Results Compared with that of the normal tissues around the tumor in the different tumor stages and grades, PKC activity in carcinoma increased significantly in plasma and membranous;with the increasing of tumor stage and grade, PKC activity increased in the tumor tissues.P-gp expression in bladder tumor tissues and normal tissues around the tumor were 90%, 100% respectively, bladder tumor tissues was lower than that of normal tissues significantly.And MRP expressed in all these tissues, bladder tumor tissues was higher than that of normal tissues significantly.P-gp had not difference in both grades and stages, and MRP increased with grades significantly, but not with stages.In addition, MRP was correlative with PKC activity, P-gp wasn’t correlative with PKC activity.Conclusion Overexpression of PKC in the bladder carcinoma tissues might contribute to the bladder multidrug resistance of bladder carcinoma, PKC might play an important role in the multidrug resistance of bladder carcinoma.