Abstract: To clarify the major virus species on tobacco and disease situation in Liangshan Prefecture of Sichuan Province, diseased leaves of tobacco, weed and crop, aphid on tobacco, thrips on weed and crop in or adjacent tobacco fields were used as materials to analyze virus population structure and occurrence situation of major species by field survey, virotome analysis and PCR detection. The results showed that: 1）Seven plant viruses from four genuses, which were six known tobacco viruses of cucumber mosaic virus (CMV), tobacco mosaic virus (TMV), chilli veinal mottle virus (ChiVMV), tobacco vein banding mosaic virus (TVBMV), potato virus Y (PVY), wild tomato mosaic virus (WTMV), and one novel of pepper vein yellows virus (PeVYV) belonging to Polerovirus, were identified in diseased leaves of tobacco. At the genus level, the richness of Cucumovirus, Tobamovirus, Potyvirus and Polerovirus were 76.266 0%, 1.251 1%, 1.207 2% and 0.000 5%, respectively. Eleven plant viruses from five genuses were identified in diseased leaves of weed and crop. 2）Six known tobacco viruses, which were TMV, PVY, CMV, tomato spotted wilt virus (TSWV), ChiVMV and tobacco leaf curl virus (TLCV), were found by field survey. 3）PCR detection and disease situation analysis showed that TMV was spread among adjacent plants by farming and wind injury.