To maintain the width of a vehicle body structure for a motorcycle wherein the rigidity of a vehicle body may be increased without increasing the width of the vehicle. Alternatively, to enable to restrain an increase in the weight of the vehicle body by realizing a vehicle body structure for a motorcycle in which the problem wherein the weight of the vehicle body increases when the rigidity of the vehicle body is increased. In a motorcycle including main pipes extending rearwardly from a head pipe, a pair of left and right down tubes are provided that extend from the head pipe obliquely downwardly. The down tubes are formed to be tapered from the head pipe toward an engine when viewed from the side of the vehicle body and to be constant in width from the head pipe toward the engine when viewed from the front of the vehicle body.