A study on soil and water conservation effects of different introduced grasses in dry-hot valley was conducted in Yunnan.It includes analysis of biomass,fresh weight and water holding capacity of leaves and stems,litter weights and water holding capacity,soil bulk density,soil porosity,soil moisture content,capillary moisture capacity,saturation moisture content,soil constitution and organic matter,soil permeability and erosion-resisting characteristics.The results showed that water holding capacity and soil improvement of three introduced grasses is Setaria sphacelata cv.Narok>Pennisetum clandestinum cv.Whitte>Trifolium semipilosum cv.Safari.Setaria sphacelata cv.Narok is the best fodder and has the highest water holding capacity and soil improvement in three grasses.Pennisetum clandestinum cv.Whitte is the second.They can be planted in Yunnan.