Abstract:The growth of the stroma of Cordyceps sinensis largely depends upon the illumination in its growth period. By increasing illumination time and light intensity, its growth height can be controlled, growth rate slowed down and the corrosion time of larva body of host insect prolonged. Ultraviolet light is able to affect the growth of stroma too. The stroma also shows the strong phototaxis in its growth period. The arrangement and formation of the perithecium vary with the illumination.