To establish the optimum artificial light illumination method for Pleurotus eryngii in closed mushroom factory system, the effects of red/blue LED light quality on growth was investigated. The following parameters fresh weight, height, width, chromaticity and hardness of the pileus were considered for studying the effect of LED light on the growth of mushroom. Pleurotus eryngii : The humidity was maintained more than 90% and temperature was 15~16℃, and CO2 density was 500ppm. The fresh weight and height were higher under red LED light (650nm, 73.1 Pmol/m2s), green LED light (525nm,89.1Pmol/m2s) comparing with blue LED light (450nm,105.8Pmol/m2s).