A more rigid front and rear half sections of the frame that easily sets the joint rigidity of the rear half section of the frame with respect to the front half section of the frame. A vehicle frame of a motorcycle includes a pair of right and left main frames extending towards the rear from the head pipe, a lower cross member mounted between the rear ends of the right and left main frames, one center frame extended downwardly from the lower cross member, and an engine mounting bracket jointed to the lower end of the center frame. The center frame is provided with a pivot, to which the rear swing arm is vertically swingably attached.