To transfer machining information such as a machining position, a machining type and tolerance by directly using three-dimensional(3D) CAD data without preparing a material shape and a two-dimensional(2D) drawing.

In the three-dimensional(3D) CAD/CAM system for transferring 3D CAD data prepared by a 3D CAD device 20 to a 3D CAM device 21 and allowing the CAM device 21 to prepare a machining path for producing a product by machining a work on the basis of the 3D CAD data, the device 20 is provided with a color attribute adding part 32 for adding a color attribute to a part requiring the processing of a cast material in the 3D CAD data and the device 21 is provided with a recognition part 37 for recognizing the part requiring the processing of the cast material on the basis of the color attribute added to the 3D CAD data.