Abstract: Analytical Hierarchy Process（AHP）is a new method of systems analysis and decision．It combines quantitative analysis and qualitative analysis．Pointing out problems in the application of AHP in the psychic system，and exploring the feasible way of establishing the best psychic structure by AHP for the first time．The psychic system must have operational definition and uniform standard for determining the best psychic structure，so this method can be used in psychological scales．This paper introduces how to offer power weights to dimensionalities of psychological scales and the method of application and validation．

Key words: Analytical Hierarchy Process, the best psychic structure, psychic system