Based on the experimental demonstration and investigation,the effects of developing utilization of siltarrester slop on the dam stability,and the protect ing measures were studied.The results show that the dam slop is the most serious erosion beltin view of both gradient and slop length;soil preparation has little influence on slop stability,neither do roots on dam permeated deformation.A fine protective benef it could be obtained by engineering soil preparat ion and plantation,and to establish forest and orchard on dam slop,the social benefit of it is also notable.