PURPOSE: To provide the headlamp optical axis adjusting device of a motorcycle capable of simply adjusting the optical axis by boring a screw driver insertion hole on a screen and a cover tube, inserting a screw driver from the front side of the screen, coupling the screw driver with an adjusting screw to adjust the optical axis, and normally inserting a rubber plug into the screw driver insertion hole.

CONSTITUTION: A gap between a screen 5 fitted to a window hole 3 on the front face of a cowling 2 and a lamp unit 10 fitted to the mount ring 12 of a lamp body 11 is sealed with a cover tube 4 and a flexible shade 7, and an optical axis adjusting screw 15 is fitted between the mount ring 12 and the rim 14 of the lamp body 11, a screw driver insertion hole 17 is bored on the screen 5 and the cover tube 4 in alignment with the axis of the optical axis adjusting screw 15, and the screw driver insertion hole 17 is closed with a rivet-like rubber plug 18.