Based on data observed from 1989 to 1998 in the Ziwuling survey station, changes of soilerosion and soil physico-mechanical properties were studied after forestland reclamation. When theman-induced factors changed the eco-environment by reclaiming forestlands, the intensity ofman-made soil erosion in reclaimed lands was 1,000 times more than that of natural erosion inforestlands. From the analysis of soil physical and mechanical properties, the clay content andphysical clay content decreased 2.74% and 3.01% respectively, and the ＞0.25 mm water stableaggregate content decreased 58.7%, the soil unit weight increased and the soil shear strengthdecreased, all of which were easier to cause soil erosion. The results of the correlation analysisshowed that the ＞0.25 mm water stable aggregate content was the greatest influencing factor on soilerosion, the partial correlated coefficient was 0.9728, and then were soil coarse grain and soil shearstrength, the partial correlated coefficients being 0.8879 and 0.6020 respectively. The relationshipsbetween the ＞0.25 mm water stable aggregate content, the soil sheer strength and the soil erosionintensity were analyzed, which showed that the first and seventh years were the turning years of thesoil erosion intensity after the forestland reclamation. The degenerative eroded soil andeco-environment formed the peculiar erosion environment, which aggravated the soil erosion rapidly.