Objective For preventing the recurrence of superficial transitional cell carcinoma of bladder. Methods Recombinant interferon-alpha and mitomycin C have been used combindly in cl inical study.42 patients were divided into two groups: recombinant interferon-a lpha plus mitomycin group and mitomycin C group.The protocol of chemoimmunoprop hylaxis include 6 weekly and 6 two weekly instillation of 3?10 7 IU recombinan t interferon-alpha plus 40mg mitomycin C in 40ml normal saline via catheter.Che moimmunotherapy was given once monthly for at least two years. Resul ts Follow-up(from 6 to 30 months with a median of 18 months)consist ed of cystoscopy and cytology with cold cup biopsies carried out every 3 months for 2 years. Recurrence after instillation of recombinant interferon-alpha plus mitomycin C was observed in only 2 (10%). Recombinant interferon-alpha plus mi tomycin C yielded better effect ive rate(P