Abstract: Briefed in the paper is the principle of the technology of welded pipe mill roll three-dimensional characteristic shaping. With Visual C++ 6.0 as the development language and ObjectARX in the AutoCAD as the development technology, the system for welded tube mill roll characteristic shaping is successfully developed under the MDT environment and by means of the roll profile characteristics-based principle and the pamameterization design technology, resulting in the integration of roll groove design, roll part parameterization plotting and three-dimensional characteristic shaping.