Abstract: In this paper, the field observation data of cultivated land and uncultivated land at Hulunbeier for two years in succession are used.The authors analysed the variations of soil hydro-thermal condition, atmospheric dynamic and thermo- dynamic condition near the ground, and surface heat balances during the periad between Spring and Summer May-June after reclamation. It is indicated that the microclimatic effects of reclamation are many sided and obvious, especially, the thermodynamic effects. So one must pay attention to the influences of reclamation such a human activity on climatic conditions.