Advances in Research Potassium Nutrient and Appliment of Cotton XIA Ying1) JIANG Cun-cang1) CHEN Fang2) LU Jian-wei1) LI Xiao-kun1) Hao Yan-shu1) ( 1) College of Resources and Environmental Sciences , Huazhong Agricultural University , Wuhan 430070 , China; 2) Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China) Abstract The article reviewed the effect of potassium fertilizer on yield and the chang trends, technique of applying fertilizer in main cotton production regions in China in recent 50 years, elaborated the effect of potassium on the nutrient function, resistance and quality.The effect of potassium fertilizer was difference in different periods and regions.In recent years, as the promotion of potassium fertilizer and increase the applied amount, the effect of potassium on increasing yield in cotton was decrease gradually in some cotton production regions. So, the necessity of potassium fertilizer, applied time and applied amount should depend on the potassium condition in soil and the rule of requirement of fertilization.