A zoom lens barrel assembly includes: a first zoom ring that supports a first lens group; a first guide ring, of which the first zoom ring is disposed on an inner side, is cam-connected to the first zoom ring to cause the first lens group to move linearly along an optical axis direction by rotation; a second zoom ring that supports a second lens group and is cam-connected to the first guide ring to move linearly along the optical axis direction; a second guide ring cam-connected to the first guide ring and configured to move linearly along the optical axis direction to rotate the first guide ring; a second cylinder configured to move linearly along the optical axis direction together with the second zoom ring while being rotated; and an external cylinder including a third lens group and is cam-connected to the second cylinder to cause the second cylinder to rotate.