Cordyceps militaris [(L.ex Fr.) Link] is an important medicinal fungi, which has the pharmacological effects of immune regulation, antitumor, antioxidant, reducing blood sugar and liver protection, and can be used for the treatment of tuberculosis, weak old people, anemia and other diseases.The contents of active components such as mannitol, polysaccharide and nucleoside are important indices for evaluating the C.militaris quality.