Field eaperiments for comparison of the effect of different tillage methods on the rice and wheat yield have been carried out in Wuzi county during the year of 1978-1979.The experiments showed that the fertility of the upper part of plowed layer was promoted and the soil structure was improved more remarkably due to a cropping of wheat.The traditional method of soil tillage included plowing and harrowing under waterlogged condition before rice transplanting,therefore the fertile surface soil was always turned over and soil structure was disintegrated.Pot experiments showed that mechanical disturbance of soil has no benefit to liberation of nutrients.No tillage after stubble cleaning led to the disturbance of soils to a minimum,and it was beneficial for the maintenance of soil structure and growth of rice.Deep ploughing in autumn was favorable for the growth of wheat and improvement of soil structure.Based on the results obtained it is recommended that a more rational tillage system might be no tillage in spring in combination with deep ploughing in autumn in this region.