Abstract: Terraces at different years in loess hilly region were chosen as subject to reveal changes in soil phyico-chemical and biological properties after slope cropland was rebuild to terraces. The results showed that slope cropland had a low content of phyico-chemical and biological quality because of serious soil erosion and improper cultivation. Soil phyico-chemical and biological properties had no remarkable change or a little drop in the first year of terracing under the action of soil disturbance and the reduction of erosion. Soil qualities (including of soil physical properties and anti-erodibility, chemical properties, microbial biomass and activity) were improved significantly with the terracing age. Soil quality index (SQI), integral indicator to reflect soil phyico-chemical and biological properties, appeared linear increasing with years by regression analysis. In brief, when slope cropland was rebuilded to terrace, soil was managed scientifically and soil quality was significantly improved.