The properties of biological soil crusts and their effects on soil water,organic matter and soil erosion on the lands abandoned during vegetation restoration in Duntan Hills,Ansai County,Shaanxi Province,which is located in the hill and gully region of the Loess Plateau,were analyzed.Results showed that:(1) after the abandonment,the coverage and thickness of biological soil crusts increased gradually with the increase of time,and the thickness varied from 0.1 to 0.3 cm;(2) the soil water content in the sample plots without biological soil crusts was higher than that in the sample plots with biological soil crusts,and the soil water content increased with the increase in soil depth within 0-40 cm of the soil surface;(3) the organic matter content within 0-10 cm of the soil surfaces in the sample plots with biological soil crusts was higher than that of the sample plots without biological soil crusts,and the relation was the same in the soil layers of 10-20 cm,but the variation was not distinct as within 0-10 cm of the soil surface;(4) after the abandonment,the amount of soil erosion decreased gradually with the increase of time,and compared with the early abandoned plots,the amount of soil erosion in the sample plots in more than 10 years decreased by 30%-80%.The results illuminate that biological soil crusts could improve the characteristics of soil surface layers on the abandoned lands during vegetation restoration,and enhance the soil ability to resist erosion.