Abstract: The strain BJ-6 of Bacillus sp. was isolated from the rhizosphere of apricot trees in Mentougou, Beijing, China, and showed strong antifungal activity to several species of plant pathogenic fungi. The fermentation medium and conditions for antifungal substances from the strain of BJ-6 were optimized by single factor experiments and orthogonal experiments. The results showed that optimum fermentation medium for antifungal substances formula was maltose 20g, peptone 100g, bran10 g,CaCO3 10g, Na2HPO3 2g ,KH2PO3 1g, and water 1000 ml. The favorable fermentation condition was determined：the age of inoculum10 h , inoculation amount 1%,fermentation temperature 30℃~35℃, rotate speed 210 r/min, fermentation time 60 h, and initial pH value of medium 9，.