Objective To study the therapeutic effect of combined antihuman IgG antibody with mitomycin(MMC) on human bladder cancer ceils and the primary mechanism. Methods In vitro an-tiproliferation effects of goat antihuman IgG antibody(Ab) with MMC, alone or together, on human bladder cancer cell line T24 were tested by MTT assay. Flow cytometer(FCM) was used to detect T24 cell apoptosis. Detections of activated caspase-3 and PARP[poly(ADP-ribose) polymerase] were carried out by Western blot analysis. In vivo antitumor effects of Ab of anti-human IgG with MMC were assessed using T24 xenograft in BALB/c nude mice model. Results The inhibitory rates of tumor growth of Ab, M MC and Ab+ MMC on T24 cell were (25.02±6.71)%, (32.31±6.46)% and (73.66±5.81)%, respectively. The rates of apoptotic cell of PBS, normal goat IgG, Ab, MMC, MMC±normal goat IgG, and MMC+Ab were 1.7%, 2.3%, 20.7%, 22.4%, 28.3% and 53.8%, respectively. Western blot shows Caspase-3 and PARP were cleaved in T24 cell during the course of apoptosis induced by Ab and MMC, and indicated that cell apoptosis was associated with caspase-3 and PARP activation. Under the treatment of normal goat IgG, Ab, MMC, and MMC+Ab, the in-hibitory rates of T24 xenografts in BALB/c nude mice were 2.31%, 12.73%, 36. 81%, and 50.51%, respectively. Histological examination demonstrated significant necrosis and apoptosis in the mice treated with alone MMC or Ab but no control goat IgG or PBS, in addition, HE displayed more extensive necrosis and apoptosis in the mice with MMC+Ab.Conclusion Antihuman IgG Ab with MMC has in vitro and in vivo inhibitory effects of human bladder cancer T24 , which are related to in-ducing cell apoptosis.