In order to provide scientific basis for vegetation restoration and reconstruction of removal lands in hilly-gully region

based on the data of Ansai in the typical semiarid loess hilly-gully region

we studied the effects of environmental factors on the community distribution

species diversity and biomass in four typical communities.The results showed that coverage

aboveground biomass and underground biomass increased a lot with the increase of abandoned time

soil water content and clay particle content had the same trend.Or- dination technique of canonical correspondence analysis (CCA) was used to examine the relationship between the communities and environmental factors.Results showed that environmental factors compositively affected the distribution and variety of communities

among which organic matter

abandonment ages

clay particle content

aspect

altitude

nitrate nitrogen had main effects on the change of typical communities of abando- ning land at the level of p<0.01.Multi-analysis and pathway analysis indicated that total phosphorus had the largest direct positive effect on the ecological dominance of communities;total nitrogen and organic mat- ter respectively had the largest direct positive effect on underground biomass and aboveground biomass.