The effects of vegetation transpiration and blocking surface runoff are researched; and three main influences of ecological slope protection on water content of slope rock-soil body and matric suction are put forward. The three aspects of influence are as follows: (1) The action of vegetation’s transpiration consumes the moisture of slope rock-soil body; and it recedes the water content of slope; increases the matric suction and benefits the stability of slope; (2) Vegetation blocks surface runoff and increases the rainfall infiltration

and it makes the water content increased

matric suction receded and disadvantage the stability of slope; (3) How the change of slope body water content and matric suction will benefit the stability of slope because of the existence of vegetation. All these decide by rainfall amount and rainfall type. Therefore

the slope must be made up into waterproof and drainage treatment for the ecological slope protection in area

with flush rainfall and torrential rain.