Abstract:cDNA of cucumber mosaic vires coat protein (CMV CP) was successfully introduced into tomato (Lycopersicon esculentum) plants by Agrobacterium tumefaciens mediated. Many transgenic plants were obtaind and these plants expressing CMV CP were highly resistants to CMV infection. cDNA of CMV CP in the genome of progeny R1 separated with 3: 1. Progeny R1 of transgenic tomatoes expressing CMV CP were protected from CMV infection. Symptom development and virus accumulation were reduced or absent in the transgenic plants expressing CMV CP. The disease ratio and disease index of transgenic plants were much lower than the controls and symptom development was delayed for more than one month compared to those of the controls.