This paper presents a method for MADM of partial weight information. The method consists of three steps --- first optimizing regionally, then forming assigned weigh and ranking all decisions. The method, according to the minimum deviation, constructs the statistics - variable of weight and contains the utilization of both samples information and previous information so as to make the evaluations objective and believable. In addition, IE is employed and optimal mathematics model is set up on the basis of the method. At last, an illustrative example is given to demonstrate the effectiveness of the new method.