AIM:To investigate the killing effects of tumor cells specific vector of suicide gene of CDglyTK driven by hTERT promoter on retinoblastoma Y79 in vivo. METHODS:The BALB/C nude mice were devided into two groups,ten mice each.The experimental mice were injected subcutaneously with the CDTK expressional retinoblastoma Y79 cells.The control mice were injected with non-transfected Y79 cells.Intraperitoneal injections with 5-FC and GCV were started 7 days after tumor injection.Tumor was allowed to grow and established.All the mice with tumor received prodrug once per day for 15 days.The volume of tumor were observed.Furthermore, the pathological results of tumor was observed.At the same time,RT-PCR was used to detect CDTK amplification fragements in the tumors. RESULTS:The volume of the tumor in experimental group,compared to the control group,showed a significant decrease.There was significant difference in the tumor volume between the two groups(P<0.05). There was generous necrosis in the transfected group.The result of RT-PCR showed 403bp fragment that was eaqual to the expection. CONCLUSION:Tumor cells specific vector of suicide gene of CDglyTK and prodrugs can inhibit the growth of tumor of Y79 subcutaneously.