Based on lane-marking tracking with fuzzy adjustable vanishing point mechanism, this paper presents robustness forward vehicle detection system. Compared to most of the detection systems with a large curvature of road trend, which are not effective for the routes to detection and marking. Therefore, follow the current image frame, the proposed system calculate the error between lane detection point and regressed lane-marking lines, and then fuzzy inference system derive and update the proper vanishing point in next image frame. The algorithm proposed in this paper can be carried out for different road situations and adaptive tuning of the car camera has been successfully tested and proven for the highway to the robustness of the system.