This document describes an automatic process planning system for users. The system collects the knowledge by the different levels and classes. It expresses the knowledge by the If- then rules and AND/OR tree structures. The process planning is antomatically generated by the rule correspondence and the depth priority. This system sets up not only inter knowledge -bank but also outer one. The outer knowledge - bank may be changed and enlarged according to the requirement of the users. So

the system may be used in different environment. It has a better flexibility.