Abstract
This paper deals with the results of investigations of factor influencing the regional variation of yield stability of the paddy rice crop. The following factors were taken into consideration, i. e., climatic conditions, atmospheric damages, soil conditions, irrigation systems, insect and disease injuries, intensity of farm management, percentage of farmers having side jobs, size of farm management, and the proportion of paddy fields to the whole farm. These various factors were closely related to the yield stability of each region respectively.
