Abstract: Provided is a lane departure warning system and method. The lane departure warning system includes an edge style classification map capture module, a road marker seed region detection module, a lane detection module, and a lane departure warning module, which can detect, by using an edge style classification map, and through road marker seed region detection and lane detection, lane edge pixels and identify real road marker edge pixels under a circumstance that there is no obvious gradient change or light is reflected or an obstacle exists, thereby determining a complete lane, and effectively finding a Region Of Interest (ROI) to simplify a procedure of lane detection.