The mathematical method of experimental design was used to develop a new enzymic medium for cultivation of Bacillus thuringiensis H14 266/2-1, a bactoculicide producer. The optimized medium based on corn flour enzyme lysate as a carbon source and fodder yeast enzyme lysate as a source of nitrogen amine made it possible to increase twice the titre biomass yield for 24 h cultivation as compared to the initial medium. The above medium does not yield to the initial production medium in the insecticide activity.