A traffic lane marking line recognition system for vehicle including a traffic lane marking line recognizing device configured to recognize at least a traffic lane marking line in broken (e.g., white) line on a road surface in a camera photographed image, and an image compositing device which composites images photographed at different time points to elongate the traffic lane marking line in the photographed image, wherein the images are composited in a processing stage in such a manner that no change will be imparted to at least a shape of the traffic lane marking line in the photographed image in a traffic lane marking line recognition processing, specifically in a processing stage prior to edge detection. With this, a distant traffic lane marking line is prevented from being chipped away when compositing the photographed images, thereby enabling accurate and unerring recognition of the traffic lane marking line.