Abstract: In order to find out the suitable climatic conditions for the occurrence and epidemic of tobacco Potato virus Y(PVY) disease,the climatic factors influencing PVY disease occurrence were investigated on the basis of disease observation data and synchronous meteorological observation data at Zhaoyang District in Zhaotong City from 2009 to 2011.The results showed that temperature,precipitation and sunshine hour closely correlated to the initial occurrence data,prosperous period,disease incidence and disease index of PVY disease. Disease incidence and index positively correlated to temperature and precipitation,while negatively correlated to sunshine hour.Higher temperature,more precipitation and less sunshine hour promoted the occurrence and spreading of PVY disease.