The effects of soil erosion control and soil improvement were researched through the observation of runoff and soil erosion,and through the analysis of some indexes of soil property in the plots of three kinds of artificial forest,Pinusyunnanesis community,Eucalyptus maidensii and mixed Acacia mearsii -Eucalyptus maidensii community and the non-forest contrast from March 1,1998 to March 1,1999. The results indicated that mixed E. maidensii -A. mersii community,P. yunnanensis were able to efficiently control surface runoff and soil erosion and there were high percentages of Si/V,stable-water aggregate,non-capillary porosity in the soil of these two artificial forests. Meanwhile,less loss of main nutrient elements happened,which was in favor of the fertility better improved and more organic matter,available N,P,K were accumulated in soil of mixed E. maidensii -A. mearsii community and P. yunnanensis community. To the contrary,both the soil erosion control and the improvement of soil were poor for the contrast and E. maidensii community. So,mixed E. maidensii -A. meamsu communities,P. yunnanensis community should be recommended for afforestation in the harnessof soil and water erosion.