Abstract: In this paper,the problem about assessing expert's weight in aggregating the group preference information of fuzzy judgment matrices is studied.The characteristic matrix of fuzzy judgment matrix and optimized model for calculating the comprehensive matrix are presented.A new method for deriving posterior weight is given based on reliability of expert's fuzzy judgment matrix.In the end,an example is presented to illustrate the approaches.

Key words: group decision-making, weight, fuzzy judgment matrix, consistency