To provide a lens mount structure which can align a lens optical axis with high accuracy without constituting a complicated lens mount structure, the lens mount structure for mounting a lens barrel to a main body of a camera, or the like, by retaining flange portions formed along an outer periphery of a base body of a lens barrel with retaining portions formed on a cylindrical mount disposed on a front of the support unit, the center of gravity of the cylindrical barrel between an front edge and the flanges, wherein reference surfaces for aligning a lens optical axis of the lens barrel mounted on the main body are formed on the respective flange portions; the reference surfaces are formed while facing the center of gravity of the lens barrel, and the reference surfaces are given a slope; and the retaining portions retain the flange portions while the reference surfaces formed on the flange portions remain in contact with retaining surfaces formed on the respective retaining portions.