Abstract: In order to improve the commodity rate of navel orange and realize scientific fertilization, the influence test of different potassium application rates on the yield and quality of navel orange were carried out in Shouning County. The results showed that the application of potassium could promote the yield and quality of navel orange. When the annual application of potassium was 600 kg·hm^-2 (T2), navel orange had the best comprehensive performance of soluble solids, fruit shape index, single fruit weight, yield, output value and economic benefit, which increased by 14.03%, 5.6%, 23.25%, 24.34%, 2,490 yuan and 2,170 yuan, respectively, all with significant or extremely significant difference comparing with CK, which without potassium. When the annual application potassium was 780 kg·hm^-2 (T3), the single fruit weight, yield, output value and economic benefit of navel orange increased slightly comparing with T2, but the soluble solids and fruit shape index decreased.