Abstract: In order to obtain the best carbon source of Cordyceps militaris artificial substitute cultivation，studied the quality and yield differences of Cordyceps militaris when 4 different kinds of crops were the main ingredient of culture medium. When the other conditions were the same，rice， sorghum，corn and wheat were used to be the culture medium，from liquid seed to fruiting body maturity. Surveyed and evaluated the quality and yield differences of fruiting bodies with random sampling. The results showed that the wheat and rice were the best carbon source，sorghum was the next while the corn was the worst.

Key words: Cordyceps militaris, artificial substitute cultivation, culture medium, carbon source