a zoom lens barrel assembly including : a first zoom ring comprising a first protrusion ; a guide ring disposed around the first zoom ring comprising a first guide slot through which the first protrusion passes , and a second guide slot ; a second zoom ring comprising a second protrusion , and movable in an axial direction ; a first cylinder comprising a guide groove into which the second protrusion inserts , and a third protrusion passing through the second guide slot , and disposed between the first and second zoom rings ; a second cylinder disposed around the guide ring comprising a fourth protrusion , a first groove portion into which the first protrusion inserts , and a second groove portion into which the third protrusion inserts , and supporting the first zoom ring and the first cylinder ; and an external cylinder disposed around the second cylinder and comprising a third groove portion into which the fourth protrusion inserts .