With ecological principals, the outbreak situations of rice migratory pests, (brownplant hopper Nilaparvata lugens (Stal ), white-backed planthopper Sogatella furcifera(Horvdth) and rice leaf-folder Cnaphalocrocis medinalis Guenee) in China, were analyzed. It isexpounded that the area and regions in which rice attacked by those pests have been expendedin recent 10 to 20 years and that the outbreaks have frequently taken place and the populationinfesting rice has gone up throughout the country since 1970' s....