Abstract: Feature-based modeling is a significant technology in the robotic welding off-line programming.However,there is not a geometric model of weld in the previous feature-based modeling systems for welding.It makes the welding intention vague and the feature extractions of welding difficult.The feature-based modeling system was established by redevelopment of Solidworks with VC++6.0.The geometric model of weld was set up and it made feature extractions of welding easier.In addition,the feature-based modeling system provides the robotic welding off-line programming system with adequate information and is successfully applied.