Abstract: The pathogen type and field occurrence rule of suspected tobacco PVX in Henan were studied with DAS-ELISA and multi-spot field experiment. The results showed that:1) the pathogen of suspected tobacco PVX in Henan was potato virus Y; 2) the symptom was light and developed slowly during 10-20 days after transplanting, it became serious and developed rapidly during 20-60 days after transplanting, while the disease index became stable beyond 60 days after transplanting; 3) the resistances of cv. Zhongyan100 and Yunyan87 showed no remarkable difference, and were much lower than the resistance of NC89.