Abstract: The manage-flood, a new concept, is firstly proposed for reservoirs engineering management, and compared with the design-flood. The same and differences between the two kind floods have been analyzed in detail. Two standards for judging the rationality of the manage-flood has been proposed in this paper, one is about such conditions that are satisfied to some management demands, and the other is about flood control safety that is satisfied to the standards. This paper summarized two kinds of analysis methods about the manage-flood. One method is based on the maximum of seasonal flood, and the other based on the maximum of the annual flood. The two methods have respective advantages and disadvantages. The results of the former can't conform completely to the flood control standards while the former has lower requirements for observed data. The results of the later can conform the flood control standards but the later has higher requirements for observed data and no application experiences.