least one pair of curved rails 8 fixed to the vehicle body 7 these curved rails 8 are provided with springs 10 which exert a resilient repelling force between slide pieces 6 and the rear support frame 9 so as to keep slide pieces 6 in close contact with the front support frame 11 in the absence of operative centrifugal force but to allow only one of the slide pieces to keep such contact with the front support frame 11 while the vehicle moves along a curve in fig3 the headlight based on the present invention is mounted on the vehicle body 7 by means of adjustable screws 12 the working principle of the headlight based on the present invention will be described below while an automobile is running in a straight direction according to the present invention the springs 10 exert a resilient force pressing the respective slide pieces 6 against the front support frame 11 and the headlight beams are directed straightly forward when the steering wheel is turned in either direction and the vehicle body starts to change its direction centrifugal force starts to act on the vehicle body therefore the direction of the rudder 1 projecting from the lamp body is changed when the direction.