Abstract: With respect to the consistency problem of expert group's judgments based on the preference information on the decision matrices in form of interval numbers, an analytic method is proposed. The concept of interval number and the method to normalize the decision matrix are introduced. Then, defining the distance between two interval numbers and decision function of consistency, an analytic method is given to the consistency of expert group's judgment including each and all elements, alternatives and indices. Meanwhile, a discrimination approach is proposed for the consistency of expert group's judgment based on the preference information on decision matrices in form of interval numbers, with a readjusting way provided if there is no consensus on the judgment. A numerical example is given to illustrate the validity of the analysis method proposed.