In order to enhance the flexibility of the robotic welding, it is necessary to generate the robot path automatically. In this paper, the automatic teaching of the welding robot for free-formed seam was implemented through the range data acquired by the laser vision sensor. The geometric modeling of objects such as the worktable and weld joint were performed from sequential range data. The orientation as well as the position of the torch was determined by the geometric models, and the path of the welding robot was automatically generated. Experiments for the free-formed seam showed that the proposed method performed sucessfully.