Objective:To observe the protective effects of Epimedium on photoreceptor cells and to provide a pharmacodynamic basis for Epimedium that used with other drugs to treat retinal degenerative diseases in clinic. MethodsFemale Balb/C mice were randomly divided into three groups: no light group, light vehicle group and Epimedium intervention group, 6 in each group. A mouse model of photoreceptor cell degeneration was prepared by light injury, and the decoction of Epimedium was given twice to the light-injured mice by intraperitoneal injection before and after the light injury. The retinal structure was examined by optical coherence tomography, and the retinal function was analyzed by electroretinogram. Retinal histopathological sections were prepared to analyze the expression of rhodopsin, opsin-M, PKC-α, calbindin-D and GFAP in retina, respectively, and TUNEL assay was conducted to analyze apoptosis of retinal cells.  Results:After the light exposure, the outer nuclear layer (ONL) of the retina was absent and the retinal function was impaired; the expression of retinal protein including rhodopsin, opsin-M, PKC-α, calbindin-D and GFAP was absent or abnormal, respectively; and a large number of TUNEL positive cells were observed in the ONL. Among Epimedium-treated mice, the structure of mouse retina was intact with proper function, the expressions of above proteins were normal compared with no-light injured mice, and the retinal apoptosis was not observed in the ONL.  Conclusion:Epimedium has a significant therapeutic effect on the photoreceptor cell degeneration induced by light injury.