In this paper,the Kexin No.1 and Shepody were used as materials.The objective of this study was to investigate the general regulation of low reducing sugar formation in potato tuber by the observation in field and analysis in lab.The experimental results indicated:with the growth of plant,the reducing sugar in potato tuber showed a decreasing tendency.Between the Kexin No.1 and Shepody,the phosphorus in different organs 、the potassium in tuber and the nitrogen in stem were the strikingly adverse...