Abstract: An inner tube of tire includes a stick-shaped hollow tube body. For installing the inner tube of tire, the tube body is wound into a ring-shaped body having an adjustable size by crossing two lateral ends through each other, so that the tube body is applied to at least two wheel rims of different diameters. Since the user or the manufacture does not need to prepare many kinds of inner tube of tires with different lengths and the inner tube of tire could be easily replaced without the need of disassembling the wheel axle component, the process of replacing or repairing the inner tube of tire is time-saving.