Abstract: The virus disease is one of the major diseases on crops. The control effects and security of antiviral agent are not as good as people’s demands till now. New antiviral agents are in dire need of researching. In this study, we isolated bacterial strain B6 from healthy and sick tobacco soil. The results presented here demonstrated the active material was protein through using cation exchange chromatography and molecular sieve chromatography. The relative molecular mass of subunit was 40.6 kD. The induced resistance to CMV in tobacco was treated by antiviral protein., and the CMV contents and the activity of PPO, POD, PAL were studied. The results showed that with the time extending of inducing, the content of CMV increased at beginning, and then decreased, at last increased again. Antiviral protein could enhance the activity of cytophylaxis enzyme such as PPO, POD and PAL.