This paper deals with the study by plot experiments, on the relationship between soil conditions of different cut-over areas and reforestation. The results showed that the hydrothermal regime of the cut-over area where trees were removed sia years ago could possibly meet the needs of growth of regenerated seedlings. Owing to the significant variation of the hydrothermal regime of the surfac soil (0-20 cm) of cut over area nn the sunny slope at high altitude, it was necessary bo take proper sheding measures for the favorable growth of seedlings. The larger amount of carbon dioxide that was evolved from the soil surface and contained in the soil of the cut-over area as compared with that of the forest land showed that the biological activities were intensified, the decomposition of organic matter was accelerated and the contents of nitrogenous nutrients were increased. All these were conducive to the improvement of soil fertility and thereby benefical to the growth of young trees and reforestation of the cut-over area.