NOVELTY - Increasing cordycepin content in Cordyceps fruiting body involves culturing red yeast, obtaining mixed solution comprising 2-4% starch, 3-5% cane sugar, 3-4% peptone, 1-5% agar, 0.7-0.9% sodium carbonate and water. The obtained solution is sterilized and then inoculated with red yeast strain at 30 degrees C. The suspension comprising 20-24 g/L maltose, 30-34 g/L peptone, 20-22 g/L mannitol, 2-4 g/L sodium nitrate, 2-4 g/L amino acid chelate zinc, 1-2 g/L potassium dihydrogen phosphate, and sterile water, is inoculated with seed liquid culture medium at 30 degrees C.    USE - Method for increasing cordycepin content in Cordyceps fruiting body (claimed).    ADVANTAGE - The method enables to increase cordycepin content in Cordyceps fruiting body by 40%.    DETAILED DESCRIPTION - Increasing cordycepin content in Cordyceps fruiting body involves culturing red yeast, obtaining mixed solution comprising 2-4% starch, 3-5% cane sugar, 3-4% peptone, 1-5% agar, 0.7-0.9% sodium carbonate and water. The obtained solution is sterilized and then inoculated with red yeast strain at 30 degrees C. The suspension comprising 20-24 g/L maltose, 30-34 g/L peptone, 20-22 g/L mannitol, 2-4 g/L sodium nitrate, 2-4 g/L amino acid chelate zinc, 1-2 g/L potassium dihydrogen phosphate, and sterile water, is inoculated with seed liquid culture medium at 30 degrees C. The 16-18% starch, 0.4-0.6% sodium nitrate, 0.6-0.8% yeast extract and 0.8-1% water of corn steep liquor are mixed to obtain seed liquid. The pH of seed liquid is regulated to 4.0. The seed liquid is fermented for 2 days. The 36-48g corn core, 8-10g potato residue, 18-22g sweet potato vine, 0.5-0.9g wheat bran, 2-3g calcium carbonate fiber and water are mixed to obtain nutrient liquid that is sterilized at 120 degrees C for 30 minutes. The Cordyceps militaris is cultured at 26 degrees C for 5-7 days. The cultured Cordyceps militaris is illuminated every days with 200 lux for not less than 10 hours at 18-25 degrees C. The illumination intensity is increased to 800-1000 lux at 22 degrees C. The air humidity is maintained at 85%. The Cordyceps militaris is ventilated by air for 3 times each days, every time for 10 minutes. The Cordyceps militaris is cultured for 15-2to obtain desired Cordyceps militaris.