Background : Recently, some of the previous stuies reported that was useful technique on growth and yield of organically grown ginseng transplantation in a rain shelter greenhouse. This study was conducted to investigate the optimum method of greenhouse shading for ginseng(Panax ginseng C. A. Meyer) cultivaton in the northern area of Ganwon, Korea. Methods and Results : We carried out to select optimal shade materials and light-penetrated ratio among polyethylene film with two-layered polyethylene net(PEF+PEN) and blue-white duplicated PE film(BWD-PEF) in the condition of greenhouse for ginseng cultivation. The order of light-penentrated ratio by shade meterials was PEN(75%)+PEF 〉 PEN(85%)+PEF 〉BWD-PEF(85%) 〉BWD-PEF(90%) and the order of air temperature was BWD-PEF(85%) 〉BWD-PEF(90%) 〉PEN+PEF(85%) 〉PEN+PEF(75%). The net photosynthetic rate was higher in PEN(75%)+PEF than other shading material treatments during growth season including summer high-temperature period. The root weight and yield were increased by 31.2~55.0% and 25.6~52.2%, respectively under PEN+PEF(75%) compared to other shading materials. Conclusion : We concluded that the PEN+PEF(75%) could be a good shading meterails of the greenhouse for organic 4-year-old ginseng cultivation in northern area of Gangwon, Korea.