This paper is a review article outlining the present state of research into the biotypes cf brown planthopper (DPH),in which the following aspects of these studies are described:1) Occurence of biotypes:2) Specificity of biotypes:3) Formation of biotypes.While cultivation of resistant rice varieties has proved to be highly effective on the BPH.their long-term stability is threatened by the appearance of prolific biotypes which can destory these varieties.Therefore,both major and minor resistant genes will be used in the present rice breeding researches for effective pest suppression.