[Object] Provided is an expansive catheter balloon that has a spreadable outer diameter controllable easily in treatments for a calcific aortic stenosis, rheumatic and congenital aortic stenosis and others, and that can be effectively prevented from being freely shifted and can easily be fixed at a predetermined position.[Solution] The catheter balloon 10 includes a cylindrical balloon part 20 that is made non-expansive or low-expansive, and a band part 30 made of a stretchable elastic body. When a stretching force is not applied, the band part 30 has a shorter diameter than a spread diameter of the balloon part 20 and is wound around the center of the balloon part 20.
