Abstract: As a traditional Chinese medicinal herb,epimedii has effects on toning kidney,strengthening bones and muscles,and treating rheumatism.Its bioactive ingredients are mainly prenylated flavonol glycosides,including icariin,epimedin A,B,and C.Two light conditions Yao-yuan (Medicinal Herb Garden) of Wuhan Botanical Garden,Yuan-wai-yuan of Wuhan Botanical Garden were used to study how light affected the biosynthesis of the major bioactive ingredients in Epimedium wushanense T.S.Ying and Epimedium sagittatum (Sieb.& Zucc.) Maxim.Results showed that the photosynthesis rate was higher in Yao-yuan than in Yuan-wai-yuan for both species.The four bioactive ingredients of E.sagittatum were higher in Yao-yuan than in Yuan-wai-yuan,but the opposite was found for E.wushanense. Photosynthesis rate had significant positive correlation with the content of epimedin A,B and icariin,but had significant negative correlation with epimedin C.The relationship between photosynthesis rate and accumulation of bioactive ingredients was discussed.Suggestions were also proposed for cultivating different Epimedium species.