Abstract: To clarifying the genetic relationship between the viruses in tobacco leaves and the viruses in neighboring crops and weeds, RT-PCR was used to detect and clone virus CPs in tobacco leaves and neighboring crops and weeds. MEGA was employed to analyze the relationships between viruses from tobacco leaves and neighboring crops and weeds in Qianjiang. The results showed that tobacco leaves in Qianjiang area contained TMV, CMV and PVY. In addition, TMV CP was isolated and cloned from Gonostegia hirta (Bl.) Miq., Rubus corchorifolius, Ipomoea batatas Lam., and Phaseolus vulgaris. CMV CP was isolated and cloned from Rubus hirsutus Thunb, Senecio scandens Buch.-Ham. ex D. Don, Gonostegia hirta (Bl.) Miq., Rubus corchorifolius, Ipomoea batatas Lam. and Phaseolus vulgaris, and PVY CP was isolated and cloned from Nicandra physalodes (Linn.) Gaertn., Ipomoea batatas Lam, weeds and Phaseolus vulgaris. Through the analysis of the evolutionary relationship, it can be concluded that Rubus corchorifolius, Phaseolus vulgaris, Gonostegia hirta (Bl.) Miq. and Ipomoea batatas Lam. are the main sources of TMV in tobacco fields, Rubus hirsutus Thunb is one of the sources of infection of CMV in tobacco fields, and Nicandra physalodes (Linn.) Gaertn. is one of the main sources of PVY in tobacco fields in Qianjiang.