The social-economic historiography of medieval Korea started with overcoming the thought of undeveloped korean history. A lot of korean historians have argued that Korean history had the own progressive one and have producted their works. Because of the tendency, the social-economic historiography have been overheated for last several years. Besides, the Marxist fashion after 1980s affected historians and reinforced the tendency. But, in late 1990s, the rich work of social-economic historiography was declined. the decline of the social-economic historiography resulted in quantitative decline of historical works. However, that quantitative decline don’t mean the decline of importance of the social-economic historiography. In order to understand the medieval Korean history, we should understand the social structure and material civilization. In this article, I was purposed to overcome the situation of depressed social-economic historiography and seek for the advance of the study. I studied the productive capacity in Goryeo Dynasty over this paper. The productive capacity depended on the tools in agriculture, especially the plow and hoe. Recently, the excavated tools proposed us much information of the plow and hoe in Goryeo Dynasty, and advanced our views of them. A several ruins of cultivation gave us the new information. For long time, the historians who studied the Goryeo’s social-economic history have debated whether there was repeated cultivation or not. Through the study of excavated farmlands. I know that the farmland near a river was the land of repeated cultivation.