通过引入信息量和条件信息量,对不完备信息系统中属性的重要性进行了定义;针对不完备数据表和不完备决策表提出了一种基于信息量和条件信息量的属性约简启发式算法,该算法的时间复杂度是多项式的.通过实例说明,该算法能得到信息表的约简和决策表的相对约简. The importance of attributes in incomplete information system is defined by introducing information quantity and conditional information quantity. A attribute reduction heuristic based on information quantity and conditional information quantity is proposed for incomplete data table and incomplete decision table. Algorithm, the time complexity of the algorithm is polynomial.An example shows that the algorithm can get the reduction of the information table and the relative reduction of the decision table.