Abstract: This article systematically explained the logic of the influence of farmer’ s operation scale on the production efficiency of ratooning rice. Using the micro-survey data of 103 ratooning rice growers in Anhui Province, the author adopts data envelopment model (DEA) to empirically analyze the production efficiency of ratooning rice in different scales. The results show that the production efficiency of ratooning rice and farmer’ s operation scale roughly present a “U-shaped” trend. Small farmers with below 3.33 hm² scale have unique advantages. So their production efficiency is effective and constant returns to scale. However, the comprehensive efficiency of 3.33～26.67 hm² scale is relatively low. When the scale is expanded to more than 26.67 hm², economies of scale plays a role and the production efficiency of ratooning rice will rebound to be effective. Therefore, it is suggested that the operation scale of ratooning race should be appropriated to the farmer’ s condition. And the farms should change their ideas to create rice brands with high-quality. Besides, the relevant departments are supposed to increase promotion efforts, organize professional training and improve subsidy policies to reduce farmer’ s input costs.