Abstract: Parametric description and graphics plotting of welding joint groove play an important role for software development of welding process design.Parametric model of joint type and groove graphics is presented based on double U-groove.Principle for joint groove graphics parameter-driven is analyzed and the function of geometry parameter dynamic labeling for groove graphics is realized.The classes for primitives plotting object-oriented are presented.The primitives-data storage structure of parameter plotting process is showed.The use of picking primitive object with mouse resolves the question of modifying the primitive properties.The generation of neutral vector WMF file and serialization process for joint graphics are discussed.The results show that parametric model and vector plotting for joint groove graphics can handle labeling for joint parameter and embed graphics distortion in report form.