To improve the spore yeild of Bacillus mucilaginous in submerged fermentation,optimizing process of the culture conditions including single factor experiments and orthogonal experiment was carried out and spore yeild according to blood cell counts board was used as an indicator. The results showed that the optimal culture conditions were:inoculation amount of 5%,initial pH of 7.5,CaCO3 amount of 6g/1000mL,broth volume of 70mL/250mL flask,rotate speed of 250r/min,temperature of 32℃ for the beginning 24h,then...