Epimedium koreanum Nakai is a perennial herb of Berberidaceae, a common traditional Chinese herb officially listed in the pharmacopoeia of the People's Republic of China and distributed in Changbaishan Mountains, coast of Japan Sea and North Korea. From the beginning, the sources of traditional Chinese herbs are mainly wildly grown plants, but this situation cannot be maintained since the growing demand of the increasing population and higher dosage devastate the natural resources. So the agricultural cultivation and wild-simulated production are efficient methods for protecting the wild resource and meeting the supply. The optimal ecological factors are keys to production. The characteristics of morphology, photosynthesis, chlorophyll content and accumulation and allocation of biomass were studied in three habitats (the open land of forest edge, forest edge and forest understory, respectively), differing mainly in light intensity and crown density. Samples and investigation were obtained on Cuocao Groove (126°39'E, 41°45'N), the Southeast foot of Changbaishan Mountains, Jilin Province, China. The parameters (Pn, Tr, Gs and Ci) of E. koreanum in different habitats were tested by LCpro+ portable photosynthesis. After testing, 20 entire plants in each habitat were grubbed up. The characteristics of morphology and the biomass of different organs in total plant were taken. The chlorophylls were extracted with acetone and the contents were determined by ultraviolet spectrophotometry. The results showed that the plant height, stem diameter, total leaf area and other morphological indexes decreased with the weakening of light intensity, the same as the Pn, WUE, Ls, Chl a/b and biomass accumulation of organs. On the contrary, the Ci, LUE, Chl b and total Chl increased. The differences at morphological indexes and biomass accumulation were significant at 0.05 level (P<0.05) and 0.01 level (P<0.01) in different habitats, respectively. The aboveground biomass at forest edge was 1.6 times and 3.1 times to that at the open land of forest edge and forest understory, respectively. As far as the biomass allocation, the leaf biomass ratio, leaf area ratio and specific leaf area increased with the weakening of light intensity. In contrast, the rhizome biomass ratio and ratio of rhizome/shoot decreased. The biomass allocation in three habitats were very significantly different (P<0.01). The aboveground biomass ratios were 0.733, 0.659 and 0.664 at the forest understory, forest edge and open land of forest edge, respectively. The utilizing light way and surviving way of E. koreanum at different habitats were different. The ecological factors of forest edge and open land of forest edge were more beneficial to clonal growth of rhizome than that of forest understory. This paper can provide a scientific basis for the utilization and management of wild resource and the bionic cultivation of E. koreanum.