In the vehicle structure for mounting an air-cooled internal combustion engine, a crankcase is supported by a body frame in such a manner that crankcase hanger bosses on the crankcase are joined to the body frame via crankcase hanger plates. A cylinder head has left and right cylinder head hanger seating surfaces formed perpendicular to a left-right horizontal direction by cutting out right and left symmetric areas close to side edges of left and right side faces of the cylinder head along with parts of cooling fins. One ends of left and right cylinder head hanger members are fastened respectively to cylinder head hanger attaching seats on which the left and right cylinder head hanger seating surfaces of the cylinder head are formed. The other ends of the left and right cylinder head hanger members are fastened individually to the body frame. The structure is capable of using an engine body itself to improve stiffness of a body frame without use of any particular reinforcing members.