Objective:To observe the killing effect on pancreatic carcinoma(PC-3) cell lines by early growth response-1(Egr-1) promoter activating herpes simplex virus thymidine kinase(TK). Methods:Adenoviral vector of pAdEgr-1-TK was generated through homologous recombination in bacteria and was transfected to human PC-3.After exposured to γ-radiation by a 60Co source,hemi-quantitated by RT-PCR respectively to detect the expression of mRNA of TK in different radiation dose groups, in which 0 Gy act as control group. Then the cells were added prodrug ganciclovir(GCV),the survival rate was evaluated by MTT method. Results:After irradiation,transfected cell lines(0.08 ± 0.03) were killed by prodrug GCV at higher percentage significantly compared with control group(0.86 ± 0.11)(P < 0.001). Conclusion:It indicated that the Egr-1 promoter caused high expression of TK gene in cancer cells after exposured to 60Co-γ,which should significantly boost the killing effect on pancreatic cancer cell with the prodrug.