Experiments of minimum and no tillage an clayey and sand loamy paddy soils were conducted in the farms north of the Yangtze River in Jiandsu from 1981 to 1984. Resalts of the experiments showed that the rice on the two soils under conditions of minimum and no tillage tended to be increased in yield, as compared with the soils under condition of conventional tillage; the loosenes of the soils could not be loept so long efter tillage, while appropriate compactness of the soils was conducive to migration and diffusion of nutrients and their absorption by crop roots in soil;minimum and no tillage was favorable for maintenance of stable structures in soil, resistance of the crops against the harmful condition and coordinatibn of the factors affecting the soil fertility.