Currently CAD/CAM systems have become more common in automated manufacturing to enhance accuracy and efficiency. However, machining efficiency and accuracy are mainly relied on the experience of the engineer. Therefore, in this research the main aim is to propose the system which automatically analyzes the characteristics of a CAD model and to extract manufacturing features. The method for analyzing shapes of a CAD model represented by triangle mesh is studied. The system can extract planar, spherical, cylindrical, hole, arc, and other curved regions. This research will improve the integration of CAD, CAM system, and is supposed to have a great potential in the application of manufacturing and other engineering fields.