Abstract: An incremental intermediate-model-based approach to convert design feature model to machining feature model is presented for the class of rough machining parts produced by milling or turning operation.A new concept named Max Machining Body(MMB) is proposed.The proposed method consists of three steps.Firstly,all the basic MMBs are generated incrementally based on the design feature history.Secondly,new MMBs are generated by merging the basic MMBs according to the types of their original features.Lastly,the intermediate model,which is composed of all the MMBs and their relative machining parameters,is converted to the machining feature model incrementally based on the machining priority rules and the user interaction strategies.The examples show that the proposed method can generate multiple meaningful machining interpretations,thus the user can obtain a reasonable machining feature interpretation automatically or conveniently.