Abstract: With respect to the consistency problem of expert group's judgement based on the reciprocal judgement matrix in terms of preferential information form, an analytic method is proposed. Introducing some definitions and characteristics of reciprocal judgement matrix, the consistency index of expert group's judgement and that of each expert's judgement are given. Then, the way to recognize the expert group's consistency, and adjust the inconsistency among the group because of different preference is expounded. According the consistency index of each expert's judgement, the level of an expert's judgement can be recognized. A numerical example is given to illustrate the use of the analytic method proposed.