Abstract: The measures of water resources development with technical feasibility can be economically and rationally analyzed by using the marginal cost analysis method.Therefore, the connotations of several measures in regional water resources development,such as saving water,treating waste water and potentializing other water sources are defined,and the characters of marginal cost curve of these measures are analyzed.According to the principle of marginal cost equilibrium and the theory of mutli-objective decision of water resources system,a method of comparative decision of marginal cost and a goal programming model are proposed to choose the optimal combination of various measures for regional water resources development.The computed example shows the feasibility and effectiveness of the proposed procedures.