This paper proposes a method to generate path of the industrial robot for tracking surface of workpiece. When the operator selects starting point and ending point from STL type data of workpiece in virtual environment, the tracking direction is determined and the plane including corresponding points are generated. Then, intersection points between the generated plane and the triangles in STL are extracted and arranged along the tracking direction. The position and orientation of the TCP(Tool Center Point) in the robot are calculated using registered translational and rotational relations between the real robot and the CAD environment. The robot can follow surface of workpiece between two selected points along generated path. The proposed methods are evaluated by the experiment with the commercial industrial robot for various surface tracking tasks using the workpiece which is given in STL format data.