In order to investigate the soil improvement by degrade sea-buckthorn forest

soil properties in 0-60 cm soil layers under slightly

moderately and severely degrade sea-buckthorn forests were measured. (1) The concentrations of soil available P and K under the three degrade sea-buckthorn forests in 0-60 cm soil layers were larger than those under undisturbed slopes. (2) The increases were significant at the level of 0.05 for the concentrations of soil available N in 40-60 cm soil layer and soil available P in 0-20 cm soil layer under slightly degrade sea-buckthorn forest. The increase was significant(at the level of 0.01) for the concentration of soil available N in 20-40 cm soil layer under slightly degrade sea-buckthorn forest(The available N content increased from 14.23 to 22.39 mg/kg in 20-40 cm soil layer). The increases were also significant(at the level of 0.05) for the concentration of soil organic matter and soil available N in 20-60 cm soil layer under moderately degrade sea-buckthorn forest. Decrease was significant(at the level of 0.05) for the concentration of soil total N in 0-20 cm soil layer under severely degrade sea-buckthorn forest. (3) The increases of soil available P in 20-40 cm soil layer under the three degrade sea-buckthorn forests were in the following order: moderately degrade forest > slightly decayed forest > severely degrade forest. Soil available P in the 0-20 and 20-40 cm soil layers increased as the following order: slightly degrade forest > moderately degrade forest > severely degrade forest.