Photosynthesis rates of ginseng (Panax quinquefolium) leaves were measured in a controlled environment at $20^{circ}C$ under the different monochromatic light such as white(W), red(R) and blue(B) to obtain basic information applicable to the colored shading material for the ginseng growth. Photosynthesis rate relative to white(W) light was generally higher in R and lower in B comparing to white(W) light. This difference was negligible at the close to the light-saturation point, whereas the difference among the monochromatic light was extended with decreasing the irradiant. It suggests that red is good in color of shading material for growth of American ginseng.