关键词: 多指标决策, Vague集, 相离度, 优劣点

Abstract: By calculating deviation degree of every alternative to ideal alternative，this paper presents the optimization model for Vague multi-attribute decision making problems which the information on attribute weights is unknown.By solving the model，the attribute weights are obtained.By introducing the definitions of optimal plan and inferior plan，the paper gives a new method.The optimal plan and the inferior plan are obtained according to fuzzy matrix.By calculating the distance of every plan to the optimal plan，the best alternative can be obtained and every alternative is ranked.Finally，a practical example demonstrates the validity of the method.

Key words: multicriteria decision making, Vague sets, deviation degree, the optimal and inferior point