The optimal conditions for growing and developing conditions of Cordyceps militaris, including carbonsource, nitrogen source, mineral salt and light quality, were primary investigated in the paper. The best medium andlight quality were selected in the experiment. The best medium for encarpium was that carbon source was 5 g/L glu-cose, nitrogen source was 5 g/L yeast extract, mineral salt was 1 g/L monopotassium phosphate, and light quality wasblue light or incandescence. Besides, the best medium for soluble sugar produced in encarpium of Cordyceps militaris was that carbon source was 5 g/L soluble starch, nitrogen source was 5 g/L peptone, mineral salt was 1 g/L magne-sium sulfate, and light quality was incandescence. On the medium of which carbon source was 5 g/L mannite, nitro-gen source was 5g/L yeast extract, mineral salt was 1 g/L monopotassium phosphate, light quality was blue light,more soluble protein in encarpium of Cordyceps militaris could be produced.