In a lighting system for a vehicle provided with a main light, an extension arranged between a reflector of the main light and an outer lens, a light guide member located in the vicinity of the extension, and a light source for the light guide member provided separately from a light source for the main light, the light source and a driver for the light guide member are arranged effectively to improve external appearance. A light incident section provided in the light guide member for admitting light from the light source for the light guide member, and a driver for the light guide member for adjusting power supply amount to the light source for the light guide member, are arranged in such a position as to be covered with an extension in a front view.