Cordyceps militaris fermentation can produce imrnunomodulatory, antioxidant, hypoglycemic and other physical activity components. In this study, adlay, rice and wheat were three different media for Cordyceps solid-state fermentation. Moreover, dried porcine soluble, spray-dried plasma protein, fish meal, and yeast powder were used as different nitrogen sources in media in order to investigate the effects of medium on production of cordycepin by Cordyceps militaris solid-state fermentation. The results showed that using wheat as a major medium and fish meal as a nitrogen source for Cordyceps militaris solid-state fermentation at 22 °C could produce the highest concentration of cordycepin, 11.3 mg/g, after 35-days fermentation.