A lens barrel assembly comprising: an inner barrel that comprises, on an outer circumferential surface thereof, a first movement pin projected outwardly and a second guide groove that is separate from the first movement pin and is extended along a circumferential direction; and an outer barrel disposed outside the inner barrel that comprises, on an inner circumferential surface thereof, a first guide groove extended along the circumferential direction to be coupled with the first movement pin, and a second movement pin that is separate from the first guide groove and is projected inwardly to be coupled with the second guide groove, wherein the inner barrel is moved relative to the outer barrel in an optical axis direction as the outer barrel rotates relative to the inner barrel, and wherein the first movement pin, first guide groove, second movement pin and second guide groove are configured such that a movement profile of the inner barrel comprises a first movement section in which the first movement pin is moved while being guided by the first guide groove, a second movement section in which the second guide groove is moved while being guided by the second movement pin, and an intersection movement section that connects the first movement section with the second movement section, wherein: in the first movement section, the first movement pin is engaged with the first guide groove, and the second movement pin is not engaged with the second guide groove; in the second movement section, the second movement pin is engaged with the second guide groove, and the first movement pin is not engaged with the first guide groove; and in the intersection movement section, the second movement pin is engaged with the second guide groove before the first movement pin is released from the first guide groove, and the first movement pin is engaged with the first guide groove before the second movement pin is released from the second guide groove. an inner barrel that comprises, on an outer circumferential surface thereof, a first movement pin projected outwardly and a second guide groove that is separate from the first movement pin and is extended along a circumferential direction; and an outer barrel disposed outside the inner barrel that comprises, on an inner circumferential surface thereof, a first guide groove extended along the circumferential direction to be coupled with the first movement pin, and a second movement pin that is separate from the first guide groove and is projected inwardly to be coupled with the second guide groove, wherein the inner barrel is moved relative to the outer barrel in an optical axis direction as the outer barrel rotates relative to the inner barrel, and wherein the first movement pin, first guide groove, second movement pin and second guide groove are configured such that a movement profile of the inner barrel comprises a first movement section in which the first movement pin is moved while being guided by the first guide groove, a second movement section in which the second guide groove is moved while being guided by the second movement pin, and an intersection movement section that connects the first movement section with the second movement section, wherein: in the first movement section, the first movement pin is engaged with the first guide groove, and the second movement pin is not engaged with the second guide groove; in the second movement section, the second movement pin is engaged with the second guide groove, and the first movement pin is not engaged with the first guide groove; and in the intersection movement section, the second movement pin is engaged with the second guide groove before the first movement pin is released from the first guide groove, and the first movement pin is engaged with the first guide groove before the second movement pin is released from the second guide groove. in the first movement section, the first movement pin is engaged with the first guide groove, and the second movement pin is not engaged with the second guide groove; in the second movement section, the second movement pin is engaged with the second guide groove, and the first movement pin is not engaged with the first guide groove; and in the intersection movement section, the second movement pin is engaged with the second guide groove before the first movement pin is released from the first guide groove, and the first movement pin is engaged with the first guide groove before the second movement pin is released from the second guide groove.