To provide a head light illumination angle control system allowing a driver of one's own vehicle to previously and more certainly visually recognizing a line shape of a curve which the one's own vehicle enters.

An illumination angle calculation part 10 calculates swivel angles 1 and 2 based on a model type "swivel angle 1=constant 6+6curve radius R+6distance L+6line shape information C" and "swivel angle 2=constant 7+7curve radius R+7distance L+7line shape information C+7slope ". Further, an illumination angle control part 20 controls a left side head lamp 50L so as to reach the swivel angle 1 calculated based on a model equation when an intrusion curve is a left curve. A right side head lamp 50R is controlled so as to reach the swivel angle 2 calculated based on the model when the intrusion curve is a right curve.