[Objective] The purpose was to enhance the yield of Bacillus subtilis and reduce its production cost.[Method] The influences of powder of soybean cake and glucose on producing spore by liquid fermentation with B.subtilis were studied by rotary regression design.[Result] The regression equation between formation rate of spore and powder of soybean cake,glucose was Y1=35.8-2.185 65X1+0.685 666X2-5.962 504X1X1-1.25X1X2-3.462 499X2X2,the linear correlation between its dependent variable and independent variable...