Sophora davidii is constant secondary shrubbery in loess hilly. Sophora davidii can develop pure shrubbery or play dominant species roles in plant community in sunny slope and half sunny slope where the other arbor and shrub trees survive difficultly in loess hilly area,which plays important role in water and soil conservation as well as soil improvement. Barren grass land as control area, Sophora davidii population structures and the characters of soil water and soil nutrition in different stage of recovery in Sophora davidii communities that was closed for 8 years, 20 years and 30 years in loess hilly were researched systematically. The analysis on relationships between recovery of community and environment factors were made. The results showed: Sophora davidii communities could be restored by closing management in loess hilly, and Sophora davidii populations could reach relative stable stage after closing for 20 years. The density, mean basal diameter, height and biomass of Sophora davidii populations in different stages of recovery is significant different: height 30 years>height in 20 years>height in 8 years>barren grass land. With the recovery of Sophora davidii community, the number of young-age Sophora davidii individuals was declined, and the number of and middle-old-age individuals was increased, but Sophora davidii population still keep trend of expanding and with developing potentiality gradually. Soil water show feebly dry layer in Sophora davidii community of different stage of recovery, and extended downward with roots of Sophora davidii individuals. Increase of soil nutrients in beginning period of recovery is quick, but is stable in last period. Environment factors that affect Sophora davidii community recovery and the population development is water factor, such as soil water and coverage of community is comparative important. Sophora davidii has strong compatibility and reproduction and population has expanding potentiality, and its excellent characters should be made use, keeping continue forthcoming closing management in order to accelerate recovery of Sophora davidii community gradually and improve condition of environment.