PROBLEM TO BE SOLVED: To provide a light distribution control system for a vehicular headlight, which allows glare to be hardly given to a preceding vehicle in distance. SOLUTION: The light distribution system 100 includes a vehicular headlight 210 capable of controlling the light distribution pattern for executing irradiation forward of a vehicle, a camera 306 for picking up images in front of the vehicle, and a vehicle control unit 302 and an irradiation control unit 228 which detect a preceding vehicle based on the image picked up by the camera 306, and controls the vehicular headlight 210 so as to irradiate the light distribution pattern eliminating any glare to the preceding vehicle. The vehicle control unit 302 and the irradiation control unit 228 irradiate the light distribution pattern suppressed in light irradiated, in a vicinity of the front side of the preceding vehicle when a preceding vehicle is not detected. COPYRIGHT: (C)2011,JPO&INPIT