Abstract: Effects of nitrogen(N) and potassium(K) fertilizer application rates on the growth,development and yield of the hybrid rice in the field were observed.It was found that the tillering number,as well as the area and dry weight of the leaves increased with the increased rate of N and K fertilizer application.The fertilizer application rates exhibited a parabolic correlation with the crop growth rate,dry weight of stem and sheath,spike dry weight,total dry matter weight and grain yield.The hybrid rice was sensitive to N fertilizer.Therefore,the application rate of N is recommended for getting the highest grain yield,but K application for a balanced economic return.For every 100 kg grain in high yield cultivation,the optimum rates of application are 1.8 kg N and 1.6 kg K2O.