In order to reduce the tomato gray mold pathogen resistance and improve the prevention and control ef-fect, the suitable growth temperature and light conditions of tomato gray mold pathogen was determined with myceli-um growth velocity method, and the commonly used chemicals and six kinds of biocontrol strains were screened too.The results showed that the pathogen of tomato gray mold could grow at 5~30℃, and the optimum temperature was25~30℃. The pathogen could not germinate above 33℃. The growth rate of pathogen was slightly faster under thelight conditions than that of the dark conditions on the whole. Chemical C was the best in prevention and control to-mato grey mold, in the first 8 d antimicrobial rate by 100%. Followed by the Chemical A, the effect of B and D waspoorer. The pathogen grew slightly faster under the light conditions than the dark conditions in chemical A plate,but much slower in chemical B and D plate. To biocontrol strains, inhibition effect of Trichoderma viride, Trichoder-ma pseudokoningii, Rhizopus nigricans, Rhizopus stolonifer were good, inhibition rate more than 65%. Antagonisticseries reached grade II. Pathogen colonies which confront Trichoderma viride, Trichoderma pseudokoningii and Rhi-zopus nigricans showed atrophy, so the inhibition effect was better. In field experiments, control effect of chemicalC, A to tomato gray mold pathogen was the highest, 69.14% and 66.01%, respectively. To biocontrol strains, the bestprevention effect was fermentation liquid, which was 61.09%, and it was in medium level of four kinds of chemicalagents.