An adjustable limb protective assembly has a main body, a first covering frame and a second covering frame. The main body has a first extending arm, a second extending arm, two holding bases, two operating elements and a jointing connector. Each extending arm has a connecting board. The holding bases are respectively connected to the extending arms adjacent the connecting boards. The operating elements are respectively and securely mounted on the connecting boards, and each one of the operating elements has an operating mount and an operating stem. The jointing connector is connected to the extending arms. The first covering frame is connected to the first extending arm and has a first supporting arm and a first covering base. The second covering frame is connected to the second extending arm and has a second supporting arm and a second covering base.