Abstract: Potato Virus Y disease is widely spread all over the tobacco production areas in China. In the present study, the infected potato tuber was determined to be the main premary source of this disaese. The popular N strain could infect Nicotiana tobacum cv. Samsun NN, Burley tobacco, Nicotiana tabacum, Nicotiana glutinosa, Nicotianal rustica L, Physalis floridana, Capsicum annuum Linn and Lycopersicum csculentum after inoculation of twenty five species of plants. The main varieties in tobacco production are highly susceptable to this virus. Investigations showed that the tobacco near potato fields and apricot orchard diseased seriously, and the amount of aphids was an important factor causing PVY disease. We constructed the mathmatic model which revealed the relation between the disease degree and the population of wings aphids. Logistic I=1/1+a^*EXP（-b^*T）was showed to be the best simulation model revealing the epidemic of PVY in Heilongjiang province and Logit（I）=2.058+0.355Logit（I₀）-0.04SQRT（Ap）was the best field prediction model, the compare regression coefficient was 0.967, and compare regression absolutely coefficient was 0.935.