Vegetation in Ziwu mountain secondary forest area undergot destruction by human be-ing and natural restoration The researched result showed that before secondary forest restora-tion,soil in this area was similar to present yellow loess soil With secodary forest restoration。soil gradually developed soil formation process was humification and leaching and soil type e-volved form yellow loess soil to brown forest soil But after forest destruction Because of severely accelerated soil erosion soil profile was gradually eroded and damaged and soil changed to yel-low loess soil.