RNAi technique has been proved as a powerful tool for plant breeding. In this paper, the coat protein of tobacco mosaic virus (TMV) was used for constructing the RNAi interference vector. The tobacco varieties K326 and Longjiang 911 were transformed via Agrobacterium tumefaciens-mediated transformation, and transgenic plants were generated. The expression analysis with real-time PCR indicated that TMV RNA had been degraded varied in different transgenic lines. Field assay revealed that 83% and 90 % transgenic plants showed immunity resistance to TMV in K326 and Longjiang 911 respectively.