Abstract:To clarify resistance and the mechanisms of rice variety to small brown planthopper, Laodelphax striatellus Fllen, antixenosis and antibiosis of 11 rice varieties to L.striatellus were tested, and relationships among nutrient contents, amount of SiO2 amount of oxalic acid and resistance of rice varieties to L.striatellus were studied. The results indicated that three japonica rice lines, Wujing15, Wuyunjing 7 and Wuyunjing8 were susceptible to L.striatellus. Four japonica varieties, such as Zhendao2, Xudao3, Yandao8 and Yangjing9538, and four hybrid rice varieties Shanyou63, Xieyou63, Xieyou136 and Fengyouxiangzhan exhibited moderate or high resistance to L.striatellus. There were close correlations between the contents of soluble sugar, starch, total free amino acids, soluble proteins and the nymphs survival rate of L.striatellus. The amount of SiO2 in leaf sheaths in Zhendao2, Xudao3 and Xieyou136 were 0.1660±0.0027, 0.1530±0.0081 and 0.1401±0.0064g/g respectively, which were obviously higher than those of susceptible check. Higher oxalic acid contents in leaves in Yangjing9538 and Zhendao2, which were 56.372±1.086 and 53.763±1.887μg/mL respectively were founded compared with susceptible check. It is suggested that the resistance of tested rice varieties to L.striatellus was caused by lower nutrient contents, and higher amount of SiO2 and oxalic acid lead to the resistance in some rice varieties, such as Zhendao2 to L.striatellus.