Abstract: Objective :To investigate the efficacy of replication-deficient adenovirus carrying theHSV/TK gene under the control of the human telomerase reverse transcriptase (hTERT) promoter andganciclovir (GCV) in a mouse xenograft model of bladder cancer. Methods :We established the modelof human bladder cancer cell line 253J xenografts in BALB/C nude mice and administered peritonealinjections of GCV and tail vein injections of Ad-hTERT-HSV-tk. Results :The Ad-hTERT-HSV-tk/GCV system more effectively suppressed tumor growth in nude mice. The tumor volume and weightwere obviously smaller compared to the control group. The apoptosis index of the Ad-hTERT-HSV-tk/GCV group was obviously higher than any other group, but the proliferation index of the Ad-hTERT-HSV-tk/GCV group was lower than in the other groups. Conclusion :The Ad-hTERT-HSV-tk/GCVsystem suppresses the growth of human bladder cancer in vivo. The HSV-TK/GCV suicide gene systemcontrolled by the hTERT promoter can be used to treat human bladder cancer, and the effect issignificant.