Abstract: To reveal the change rule of evaporation and permeation in Shiyang River Basin, based on the LG-I weighing lysimeter, the authors studied the effects of different environmental factors on the change of evaporation and permeation under three example weather years and different seasonal background. Through the correlation comparison between each environmental factor and the evaporation and permeation, the results showed that: the effective extent order of the environmental factors was: precipitation＞temperature＞relative humidity＞wind speed. The precipitation influenced most directly and had a high correlation with the precipitation and permeation. The other factors indirectly affected the evaporation and permeation. The correlation between each environmental factor and the evaporation and permeation in the year with the most precipitation was higher than that in other years, and the above mentioned correlation in summer was higher than that in other seasons.