Abstract: To clarify the relationship between greenhouse temperature and humidity and tomato gray mould ,and the sensitivity of different medicaments to the pathogens, the greenhouse temperature and humidity and disease incidence were observed and laboratory toxicity tests were performed. The test production curve showed that the low incidence of the greenhouse reached the peak in April,at this time the temperature was 17.3%,and the relative humidity was 75%~90%. It is found that low temperature and high humidity are the necessary conditions for the disease of tomato gray mould. The virulence of Botrytis cinerea to four insecticides were measured and calculated ECho the colony diameter by mycelium growth rate method results showed that cultured for 10 days, the inhibitory effect of medicament in order,70% pyrimethanil 99.97%〉60% thiabendazole 83.43%〉80% Thiophanate-methyl 77.65%〉50% iprodione 75.81%.