Abstract: The purpose of this study is to improve the forming rate and the quantity of Bacillus megaterium C₂ spores. The medial components and cultural conditions of Bacillus megaterium C₂ were optimized by single factor and orthogonal tests in shake-flask fermentation. The results showed that the optimal medial components were composed of 1.5% bran, 1.5% soybean meal powder, NaCl 0.5%, 0.02% CaCO₃, 0.02% MnSO₄·H₂O and 0.02% MgS0₄·7H₂O. The optimal culture conditions were at temperature 37℃ with initial pH 7.0 and incubation time 48 h. Under these optimum conditions, ormation rate of Bacillus megaterium C₂ achieves 100%. The foundation for the application of Bacillus megaterium as a kind of microbial fertilizer was laid.