Flood classification is one of the important means to describe the characteristics and regularity of floods and to strengthen floodmanagement. In this paper, the Jiuzhou Station in the Lancangjiang River Basin was taken as an example, in which 198 floods were sampled byusing POT sampling method. The essential features of flood classification in this area were studied respectively from just considering theintensity index or considering the intensity and morphology index. The results are as follows: (1) The flood classification based on intensityindex can not take into account the flood intensity and morphological characteristics. The morphology is different in the same type of flood,making the flood classification results unreasonable; (2) Considering the intensity and morphology index, the floods at the Jiuzhou Station canbe divided into 4 categories. Various floods have different intensity and morphology indexes while congener floods show high similarity.