The technology of eco-protection has been widely used in various slopes.For rock slope eco-protection,the stability of substrate which provides the required soil environment for the growth of vegetation is a key factor that determins the effect of ecological restoration.The stability of the substrate is affected by many factors,such as the composition and strength of substrate and the surface roughness of rock slope.In this paper,it simply introduces several comparatively mature and commonly used technologies of eco-protection for rock slope and methods to describe joint roughness.It also analyzes the effect of rock slope surface roughness on the stability of the substrate of eco-protection and provides some suggestions for the application of rock slope eco-protection.