In order to quantify the effect of evaporation from foliage on the indoor moisture environment and obtain the basic data for the rate of evaporation from foliage, experiments to grasp fundamental characteristics and a series of experiments using design of experiment theory based on orthogonal array, were carried out. Transitional response of evaporation rate derived from sudden change of illuminance and ratio of evaporation rate from foliage to total evaporation rate including evaporation from ground surface, were confirmed. Five main factors such as temperature, relative humidity, illuminance, kind of sound and air velocity were picked up and laid out on the orthogonal table L_<27>(3^<13>). Considering indoor environment. levels for five factors were fixed, that is, 10/20/30℃ as a level of temperature, 40/60/80 % as a level of relative humidity, 0/750/1500 lx as a level of illuminance, conversational sound/music/noise as a level of sound, and 0/0.3/0.6 m/s as a level of air velocity. Results showed that relative humidity and illuminance were significant on the evaporation rate, in particular.
