An auto lighting system that turns on or off automotive lights in accordance with a brightness ahead of a vehicle, the auto lighting system comprising: imaging means for capturing an image of a road ahead of the vehicle that includes brightness recognition means for recognizing a brightness ahead of the vehicle based on the image; and lighting control means for performing lighting control by turning on or off the lights based on the image captured with the imaging means, wherein the lighting control means turns on or off the lights based on the brightness recognized by the brightness recognition means; wherein the brightness recognition means includes brightness judgment area setting means for setting a brightness judgment area in the image based on at least one of a driving condition of the vehicle and an environmental condition of the vehicle, and brightness calculation means for calculating a brightness of the brightness judgment area set by the brightness judgment area setting means; wherein the auto lighting system further comprises an information collection means for collecting vehicle information concerning a vehicle driving condition such as a vehicle speed or a steering angle and information on an environmental condition of the vehicle such as lanes of the road on which the vehicle is driving or the presence or absence of a preceding vehicle, wherein the brightness judgment area setting means sets the brightness judgment area based on the vehicle information or the information on the environmental condition of the vehicle, wherein, the lighting control means includes: light mode selection means that selects, from among three light modes including "LIGHT OFF" in which the lights are turned off, "SMALL LIGHT ON" in which small lights are turned on, and "HEADLIGHT ON" in which headlights are turned on, the "LIGHT OFF" when the brightness recognized by the brightness recognition means is greater than or equal to a predetermined first reference value, selects the "SMALL LIGHT ON" when the brightness is higher than a predetermined second reference value and lower than the predetermined first reference value, and selects the "HEADLIGHT ON" when the brightness is lower than the predetermined second reference value; and light-driving means that drives the lights in accordance with the light mode selected by the light mode selection means. imaging means for capturing an image of a road ahead of the vehicle that includes brightness recognition means for recognizing a brightness ahead of the vehicle based on the image; and lighting control means for performing lighting control by turning on or off the lights based on the image captured with the imaging means, wherein the lighting control means turns on or off the lights based on the brightness recognized by the brightness recognition means; wherein the brightness recognition means includes brightness judgment area setting means for setting a brightness judgment area in the image based on at least one of a driving condition of the vehicle and an environmental condition of the vehicle, and brightness calculation means for calculating a brightness of the brightness judgment area set by the brightness judgment area setting means; wherein the auto lighting system further comprises an information collection means for collecting vehicle information concerning a vehicle driving condition such as a vehicle speed or a steering angle and information on an environmental condition of the vehicle such as lanes of the road on which the vehicle is driving or the presence or absence of a preceding vehicle, wherein the brightness judgment area setting means sets the brightness judgment area based on the vehicle information or the information on the environmental condition of the vehicle, wherein, the lighting control means includes: light mode selection means that selects, from among three light modes including "LIGHT OFF" in which the lights are turned off, "SMALL LIGHT ON" in which small lights are turned on, and "HEADLIGHT ON" in which headlights are turned on, the "LIGHT OFF" when the brightness recognized by the brightness recognition means is greater than or equal to a predetermined first reference value, selects the "SMALL LIGHT ON" when the brightness is higher than a predetermined second reference value and lower than the predetermined first reference value, and selects the "HEADLIGHT ON" when the brightness is lower than the predetermined second reference value; and light-driving means that drives the lights in accordance with the light mode selected by the light mode selection means. light mode selection means that selects, from among three light modes including "LIGHT OFF" in which the lights are turned off, "SMALL LIGHT ON" in which small lights are turned on, and "HEADLIGHT ON" in which headlights are turned on, the "LIGHT OFF" when the brightness recognized by the brightness recognition means is greater than or equal to a predetermined first reference value, selects the "SMALL LIGHT ON" when the brightness is higher than a predetermined second reference value and lower than the predetermined first reference value, and selects the "HEADLIGHT ON" when the brightness is lower than the predetermined second reference value; and light-driving means that drives the lights in accordance with the light mode selected by the light mode selection means.