Abstract: From 1962 to 1964,we have studied the changes of soil moisture,the seasonal growth and transpiration of the trees planted in four young plantations at the Mount Miao-Feng near Peking.It is found that drought is a dominating factor affecting seasonal growth of diameter and course of transpiration.In the season with high air temperature and low soil moisture,from the beginning of June to the middle of July,tree growth is much retarded and intensity of transpiration is reduced greatly.Among the 4 species studied,Robinia pseudoacacia is more sensitive to drought than Platycladus orientalis and Quercus variabilis.Drought resistance of Pinus tabulaeformis is lower than the latter two species,but is higher than the former one.Based on this study,choise of species at the lower elevation in northern China is discussed.