A zoom lens barrel assembly is disclosed. The zoom lens barrel assembly includes: an outer barrel provided on the inner peripheral surface thereof with at least one key guide groove and at least one cam groove; a middle barrel fitted into the outer barrel and provided on the outer peripheral surface of the front portion thereof with at least one guide key, a flange and a circumferential groove adjacent to the flange, wherein the guide key is positioned in the key guide groove of the outer barrel; a middle guide ring rotatably mounted on the front end of the middle barrel, and having at least one penetrated hole on the outer periphery thereof and a slider way therein; and at least one cam follower pin, one end of which is piercing through the penetrated hole of the guide ring and disposed in the circumferential groove of the middle barrel and the other end of which is movable disposed in said cam groove of said outer barrel.