In view of the complexity of the optical properties of caseⅡ waters and its close relationship with human production activities，it is of important significance to classify them optically to improve the inversion accuracy of water color parameters and to monitor the water quality of caseⅡ waters.In this article，the optical classification methods of caseⅡ waters used in recent years are summarized and evaluated，including：Classification of water based on spectral shape；Supervised classification；Cluster analysis；Multi-band ratio method.In view of the problems existing in the current classification methods，it is proposed that the future research needs to pay more focus on reflectance spectral curves， develop hyperspectral data， comprehensively utilize multi-source remote sensing data， and establish a complete classification system for caseⅡwaters.