Abstract: In order to determine the optimum conditions of cordyceps militaris carotenoids, single factor experiment and response surface experiment were carried out to explore the complex enzymatic method optimum process conditions of cordyceps militaris carotenoids. Ultraviolet spectrum method was used to measure its antioxidant activity in vitro. The acitivity was compared with the antioxidant activity obtained by the traditional acid heat extraction.The results show that under the conditions of cellulase∶pectinase (2∶1), the enzymolysis time is 45 min、enzymolysis temperature 50 ℃、pH=4、the concentration of enzymes 0.5%. The extraction rate of Carotenoids from Cordyceps militaris is up to 3 796.23 μg/g under the optimum extraction parameters, which gets a big improvement compared with acid-heating method. The in vitro antioxidant activity assay shows that the total antioxidant capacity of carotenoids obtained by the complex enzymatic method is 4.151 U/mg, and that of carotenoids obtained by the acid heat extraction method is 4.096 U/mg. In other words, the antioxidant activities of cordyceps militaris carotenoids obtained by the two extraction methods were not significantly different in vitro.