Abstract: Rough set is applied to the problems of multi-attribute decision making.Through introducing the integrated impersonal weight，it can give a new algorithm of decision making based on the existed decision case.The fundamental ideas are as follows.A decision table is set up according to the existed decision case； then the weights of condition attributes are calculated，using the concepts about importance of attributes，local weight and global weight； and then the integrated impersonal and subjective weight are regulated through experiential factor，and get the final weight of all attributes； and then it calculates the next decision object’s decision value by applying the above weights.The decision value is the accordance of the decision making.At last，an example is given to show the practical value of the method.

Key words: rough set, multi-attribute decision making, integrated impersonal weights, decision case

摘要： 将Rough集应用于多属性决策问题，通过引入属性的综合客观权重给出一种依据已有决策案例进行决策的新算法。其基本思想是： 首先根据已有决策案例建立决策表；然后应用条件属性关于决策属性的重要度、决策案例的局部权重和全局权重等概念确定各属性的综合客观权重； 再通过经验因子来调整综合客观权重和主观权重的比例，得到各属性的最终权重； 最后利用所得权重计算待决策对象的决策属性值，以此进行决策。文中通过对实例的分析，说明了该算法的实用性。

关键词: Rough集, 多属性决策, 综合客观权重, 决策案例