Ecosystem self-rehabilitation is an important component of vegetation restoration in the loess hilly and gully region.Using natural and artificial grassland as controls, this study considered vegetation succession,aboveground biomass and soil infiltration in slope land subject to the conversion of farm land to natural vegetation.The results show that after land use conversion, the natural vegetation communities soon exhibited positive succession,with increasing biomass and improving soil infiltration. It is possible that within 20 years, the annual surface soil infiltration could increase by 0.01mm/m in and could reach to 40cm in depth.It is suggested that converting slope farm land to natural grassland is an effective approach to improve soil infiltratioin, and consequently, soil conservation.