We propose a new method for three dimensional localization of vehicle headlights in surveillance camera images at night time.It is impossible to estimate the three dimensional position of a vehicle headlight only by using the position of the headlight in images.We estimate the three dimensional position from the positional relationship of the headlight and its reflection on road surface.The reflection on the road is observed weakly and it cannot be detected by a conventional computer vision method.We detect the reflection position of the headlight by defining a scan line based on the spatial constraint of the headlight.