Returning farmland to forest is an effective measure to control soil erosion in Guizhou Province.Analyzing the quantity of the slope farmland

especially the proportion of farmland to the territory area

is an important foundation for making the strategy on the returning farmland to forest.On the basis of probing into the present situation and factors of slope farmland

this study classified the 82 counties into seven levels and three categories

taking the proportion as the urgent index of returning farmland to forest.The important region was found to be the region of the utmost key type and the key type of returning farmland

which covers 56.63 percent of the territory of the whole province.Therefore

it may achieve 75.39 percent of slope farmland to forest.As the same time

this paper presents the principle of the ratio of the grove species deployment.