Abstract: An adjustable jointer of an elastic ring for wheel shroud has a diameter which is able to be changed by adjusting the length of the jointer. The elastic ring consists of an elastic ring attached on a jointer, in which the jointer comprises a socket joint and a plug joint connecting together in plug-in joint. There are one or more collars attaching on the outside surface of the socket joint, which can be tore off to put on the latch of the plug joint to stretch the length of the jointer so as to increase the diameter of the elastic ring. Therefore by adding or removing the number of said collars, the diameter of the elastic ring can be changed to reach the goal of suiting different sizes of the wheel shrouds.