Cordyceps, one of the most valued traditional Chinese medicines, consists of the dried fungusCordyceps sinensis growing on the larva of caterpillar. It is also known as “winter-worm andsummer-grass” because of its appearance during different seasons. The parasitic complex of thefungus and the caterpillar is found in soil of a prairie at an elevation of 3,500 to 5,000 meters innorthwestern part of China. According to Chinese medicinal theory, Cordyceps is used toreplenish the kidney and soothe the lung, and indeed many clinical applications have beenreported. The natural Cordyceps is rare and expensive on the local market, and therefore, severalmycelial strains have been isolated from natural Cordyceps and manufactured in large quantitiesby fermentation technology, and they are commonly sold as health food products in Orient. Theadulterants of Cordyceps are commonly found on the market, and therefore the authentication ofthese products has to be defined. Having the urgent need from current market, different chemicalmarkers such as nucleoside, ergosterol, mannitol and polysaccharide are being used for qualitycontrol of Cordyceps. Unfortunately, these markers are far from optimization, and thereforeextensive works are needed to define the pharmacological efficiency of these markers.