Abstract: On analyzing the scheme of form feature classification according to their geometric property, a form feature classification scheme based on manufacture to meet the different needs of CAD,CAPP and NC systems is introduced. In addition,the exchanging relation between the form feature classification based on geometry and based on manufacture is discussed. With the manufacturable, unmanufacturable and modifying class presenting the form feature type, the correspondence between form feature classes and machine ways is proposed. And with the object\|oriented technology and feature manufacturability analyzing function, a scheme of form feature representation in hierarchical level is presented in this paper.

Key words: shapes, characteristics　manufacturing, classifications, systems integration