Abstract: Studies in Jianghuai hilly region showed that at definite Nand Plevels, applying potash fertilizer could regulate the transportation and distribution of nutrients in peanut plants, accelerate their absorption of N, Pand K, increase the dry matter accumulation in their reproductive organs, and increase their yield, quality, and disease resistance. For each 100 kg pod products, the absorption of N, P and K was 3.08～5.35 kg, 0.6～1.2 kg and 3.45～6.66 kg, respectively. The Kabsorption was the biggest, and it was accumulated mainly in nutritive organs. The absorbed N and P were mainly accumulated in pods and other reproductive organs. The contents of N, P and K in all organs were increased with increasing potassium levels, and the amount of increased Kwas the biggest. The yield and economic benefit were the highest when the amount of applied potassium reached to 150～180 kg·hm^-2 and N:P:K=2:1:2. The highest pod yield was 5425.5 kg·hm^-2, the highest benefit was 13878.7 yuan·hm^-2, and the ratio of output/input reached 6.75:1. The yield and economic benefit of peanut were decreased obviously when the amount of applied potassium was over 225 kg·hm^-2. Thus, the prescription of N 150, P75 and K150 was recommended for the balance fertilization of peanut production in this region.