Abstract: Objective To observe the correlation between telomerase activity and apoptosis in Hela cells induced by influenza viruses. Methods Hela cells were observed in the electron microscope after they had been infected by influenza viruses type A1, B and ultraviolet exposed influenza virus respectively. Besides, Annexin V-FITC staining flow cytometry （FCM） and PCR-ELISA were used to detect cell apoptosis and telomerase activity in Hela cells respectively. Results The maximal rate of apoptotic cells induced by influenza virus type B and A1 were 38.65% and 23.94% respectively (P<0.01). The ultraviolet exposed influenza virus maybe have certain ability to induce the apoptosis in Hela cells. Furthermore, the telomerase activity in Hela cells decreased. The decrease induced by influenza virus type B was more apparently than influenza virus type A1 (P<0.01). Conclusion It is probable another important mechanism of inducing the apoptosis in tumer cells that influenza viruses can decrease its telomerase activity.