A study conducted in laboratory to evaluate the resistance of some dominant rice varieties cultivating in the northem region of Vietnam to brown planthopper and white backed planthopper. The result shows that in 22 rice varieties (15 conventional varieties and 7 hybrid varieties) infected with brown planthopper, there were 2 moderately resistant varieties Xi 23 and TH3-3, 3 moderately susceptible varieties C70, VL20, VL24 and other 15 varieties highly susceptible. In 12 rice varieties (8 conventional varieties and 4 hybrid varieties) tested with white backed planthopper, 1 moderately resistant variety CR203, 1 moderately susceptible variety TH3-8, 3 susceptible varieties T10, IR64, BC15 and 7 highly susceptible varieties were recorded.