Abstract: Most of the granular slopes exist in western mountainous areas of China. Granular slopes, which are made up of different sizes of lumpiness and few clay particles, are easy to collapse because of weak cementation between particles, rain eroding & wind eroding or the people and animals’ tread. Traditional technologies for slope protection contain frame and geo-grid with plants. A new method involves geotechnical materials and ecological environment and focuses on the surface protection of slope by using topsoil which is stabilized with 1.3% of the modified sodium carboxymethyl cellulose (M-CMC) as well as plant fiber. Two traditional methods (rhombic frame beams and geo-grid) and this new environmental method for soil modification are used to increase the stability of a granular slope in the field in this study and natural slopes are taken as references. The values of soil loss, moisture content and vegetation deterioration rate of slopes suffering from rainfall and runoff erosion are observed and collected. Under the same condition of vegetation, it is found that the sediment yield, erosion deformation, infiltration rate of moisture and lodging rate of slope stabilized by M-CMC are much less than those of natural slopes and slopes stabilized by frame beams and geo-grid. The value of these indexes of natural slopes is less than that of frame beams and geo-grid. As a result, the slope treated with M-CMC protection is better than that with geo-grid, frame beams and natural slope.