Abstract: Objective:Intra-bladder perfusion of small dosage of BCG vaccine was applied in the prevention of postoperation bladder cancer recurrence.The result of the method and decrease of side reaction caused by it were investigated.Methods:5mg of BCG vaccine were poured into the bladder after operation in 167 patients who were diagnosed as superficial bladder cancer.Results:After clinical application and follow-up,the recurrence rate was 16 7%.The result was obvious and the complication decreased remarkably.Conclusion:The application of intra-bladder perfusion of small dosage of BCG vaccine will not decrease the clinical result and can decrease the side reaction remarkably so that prolong the treatment period.It is a good method,which needs advanced investigation.