Abstract: The impact of different amounts of potassium and silicon fertilizer on the features of stalk basal internode structure and lodging resistance of ⅡYou 838 was studied.The results show that potassium can significantly improve the breaking resistance of basal internode and reducing the lodging index.The best potassium concentration to improve lodging resistance of rice is 12 kg/hm2,it can make the breaking resistance increased by 97.76% and cellulose increased by 27.93%,lodging index and culm length decreased by 55.68% and 13.18% respectively.Silicon can improve the breaking resistance of the stem,shorten length of basal internode,thicken stem and improve plumpness.With the usage of 120 kg/hm2,the breaking resistance significantly increased and lodging index significantly reduced.Applications of potassium and silicon can increases culm vascular bundles area and effectively improve the vascular system of culm.Application of a certain concentration of potassium and silicon can improve cellulose and lignin content of the basal internode,but the application of potassium mainly improves the lodging resistance of N3 section,the application of silicon improves lodging resistance of N2 section.