[ ObjeeUve ] To search for the beneficial microorganisms and their metabolic products with control effect against rice Mast, the paper studied the inhibi- tion effect of the fermentation broth of actinomycetes BOS-013 strain against the pathogen of rice blast （Pyricularia oryzae）. [ Method ] With P. oryzae as the target indicator fungus, the inhibition effect of the fermentation broth of BOS-013 strain and its extracts from different solvents against the pathogen were determined using cylinder plate method and filter paper method. [ Result] The results showed that the inhibition rate of the fermentation broth of BOS-013 strain with fungus amount of 4×10^8 cfu/ml against P. oryzae was 92.0% ±0.5% ; the fermentation broth still had inhibition effect against P. oryaae after inactivation under high temperature and high pressure, and the inhibition rate was 60.0%±0.5%. After absorbed by non-polar CAD-45 type macroperous adsorption resin and eluted by 60% etha- nol, the antifungal activity of the fermentation broth was still high, and the diameter of inhibition zone reached 33.0 mm. [ Conclusion] The fermentation broth of BOS-O13 strain had significant inhibition effect against P. oryzae. The results would provide foundation for further clarification of inhibition mechanism of BOS-013 strain fermentation broth against P. oryzae and its practical application.
