Abstract: The research object is to study the growth characteristics of human Retinal Pigment Epithelium (hRPE) cells, and to investigate the damage to them which is induced by visual light. Inverted phase contrast microscope and transmission electron microscope were used to observe the morphology and microstructures of hRPE cells, respectively. Growth curve was depicted by both cells counting and MTT methods. Exposure time, FBS is free or not, replacing medium or not, and incubation time post irradiation were selected as the factors to estimate the photo-damage in hRPE cells. The results show that the hRPE cells incubated in vitro are polygonal and polarized, normal organelle and vigorous growth are also observed. The illumination for two hours with an intensity of (8,423±359)lx had already caused photo-damage. Exposed for five hours with 10% FBS in medium which is not replaced post irradiation and incubated for 24h subsequently, the damage rate of hPRE cells goes up to 58%. In conclusion, the hRPE cells cultured in vitro show normal morphology and regular growth rhythm. Visual light could cause damage to hRPE cells and the damage degree is correlated with the illumination duration and post-incubating time. Therefore the illumination directly from the sun should be avoided and reducing the illumination duration in order to protect human eyes.