This study explored a method for CAD of removable partial denture (RPD) framework, which contributes to the development of a specialized software system used in restorative dentistry. Point cloud data of a mandibular partially edentulous cast was captured by an optical scanning system with projective grating and high-resolution digital camera. The 3D model of the cast was rebuilt by a CAD software system from the 3D cloud points. Based on the principle of clinical design, the digital survey line and inserting path were determined automaticly. The tissue surfaces and polishing surfaces of every component of RPD were built also by the CAD software. Furthermore, the characteristic structures of the framework including the lingual bar, the internal and external finish lines, the tissue stop were fabricated on the base of the rebuilt model. 3D surface model of the RPD framework was created at last. In this study, geometric model of the RPD framework was fabricated successfully, which took on good fitting, high visibility and easy to modify, and the data converted to STL format that could be read by any other CAD/CAM software system was in preparation for subsequent computer aided manufacture (CAM) of RPD framework.