In order to study the roles of meadow brome in soil and water conservation, 6 runoff plots were established on a 25 sloping land in Yanqing County.Soil loss, soil water content, soil compaction, and the root system were measured.Results showed that the effects of meadow brome planted on the slope were evident in preventing soil loss.Soil and water loss descended with the coverage increasing.When the coverage was 90% , the yearly amount of surface runoff and soil erosion modulus were 14 233.19 m³/ km²and 57.82 t/( km²! a) , respectively, and the capabilities of water conservation and soil conservation were 67.8% and 98.31%, respectively.Meadow brome planting effectively increased the compaction within 30 cm of surfacesoil.Especially at 10 cm soil depth, the compaction was 1.72 times of CK.The water dynamic change of the soil covered by meadow brome was gentle in comparison with that of CK.Meadow brome maintained the water content in the soil obviously.The root system was mainly distributed in the soil layer of 30 cm, accounting for 98.1%.