Abstract: OBJECTIVE To compare the effect and safety of intravesical instillation of pirarubicin by two methods on preventing recurrence of superficial bladder cancer. METHODS All of 80 cases with bladder cancer after transurethral bladder tumor resection (TUR-BT) were divided into two groups in random. All cases accepted intravesical instillation of pirarubicin 40 mg in one week after operation, once a week for 8 weeks, then once a month for 1 year. The test group used THP 40 mg+ distilled water 80 mL, the control group used THP 40 mg+distilled water 40 mL. RESULTS All cases were followed-up 2 years after operation, the recurrence rate was no statistical significance between two groups(P>0.05), but the incidence rates of the adverse reaction in test group was significantly lower than control group(P<0.05). CONCLUSION Intravesical instillation of THP 40 mg+distilled water 80 mL can obviously reduce the adverse reaction, and it is worth recommending.