The satellite remote sensing technology, the method of the surface run off collection of erosion plot and the evaluation method of agricultural eco-economy are used to investigate the soil erosion, the situation of land use, the storage volume of soil and water conservation woods, the coverage of forest and grass, the increasing output of grain, the storage volume of closure-preserved forest and young growth in restored Longchuan small watershed, Muding county, Yunnan province, which has been harnessed for 8 years. It indicates that after five-year harness and preservation, the soil erosion amount decreases from 594.00t of 1989 to 177.00 t of 1997, as occupies 29. 7% of the 1989s erosion amount. Among the types of land use, the square of dry land decreases 499.40hm²;the one of terrace increases 517hm²; the square of man-made woods increases 9484 hm². The storage amount of soil and water conservation woods is 223460m³ per year and that of closure preserved forest and young grow this 53171 m³. The coverage of forest and grass goes up to 74.6% of 1997 from 38. 95% of 1989; the total amount of grain is 2.89× 10⁷ kg, increased by 34.3%; the amount of agricultural productis 4935kg /hm²; the pure income of a farmer is 511 yuan.