Abstract: To clarify the major types and occurrence of tobacco viruses in Liangshan Prefecture of Sichuan Province, diseased leaves of tobacco plants, leaves of weeds in tobacco fields and neighboring crops, aphids on tobacco, thrips on weeds and other crops were collected to analyze virus population structure and occurrence of major virus species by field survey, viral metagenomics analysis and PCR detection. The results showed that: 1)Seven viruses belonging to four genuses were identified in diseased tobacco leaves. Among them, six were known tobacco viruses including 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, pepper vein yellows virus (PeVYV) belonging to Polerovirus, was novel. At the genus level, the abundance of Cucumovirus, Tobamovirus, Potyvirus and Polerovirus was 76.266 0%, 1.251 1%, 1.207 2% and 0.000 5%, respectively. Eleven plant viruses belonging to five genuses were identified in leaves of weeds in tobacco fields and neighboring crops. 2)Six known tobacco viruses including TMV, PVY, CMV, tomato spotted wilt virus (TSWV), ChiVMV and tobacco leaf curl virus (TLCV) were identified by field survey. 3)PCR detection and disease occurrence analysis showed that farming and wind damage caused TMV transmission between neighboring tobacco plants.