Abstract: In this study, the classification status and antifungal activity of a marine strain Trichoderma TCS007 was studied, as well as its tolerance to 3 environment stress factors (low temperature, high temperature and salt). The strain TCS007 displayed a high tolerance performance to salt stress, and it was identified as Trichoderma asperellum based on morphology and ITS sequence analysis. Results of plate confrontation test indicated that strain TCS007 displayed 56.65%-87.62% inhibition against 16 phytopathogenic fungus. The highest inhibition rate was observed in the case of Gaeumannomyces graminsis. The ethyl acetate extract of TCS007 fermentation filtrate exhibited remarkable inhibiting effect against Sclerotinia sclerotium, and the EC₅₀ value was 38.80 μg/mL. Results demonstrated that the marine stain T. asperellum TCS007 and its metabolite showed outstanding antifungal activities, which had the potential to be developed as biological control agents for phytopathogenic fungus.