Abstract: To determine the friction characteristics of the interface between the ecological bag and riverbank slope soil,the direct shear test of the interface between the ecological bag and riverbank slope soil is carried out with the ecological bag used for river bank slope treatment as the test material,and the effects of soil dry density and water content on the friction characteristics of the interface between the ecological bag and riverbank slope soil are analyzed. The results show that the shear strength of the interface between soil and ecological bag decreases with the increase in water content,and increases with the increase in the dry density of soil. At the same time,the interface friction coefficient between the ecological bag and slope soil decreases with the increase in water content and increases with the increase in soil dry density. In addition,under the same conditions,the friction coefficient between sandy soil slope and the ecological bag is smaller than that of cohesive soil slope. The research results have a certain reference value for the application of ecological bag slope protection technology in river ecological treatment engineering.