A rapid exchange type medical elongated body is disclosed in which an outer diameter of a distal portion of a tubular member is set smaller than an outer diameter of a proximal portion of the tubular member, which prevents an occurrence of a kink in a physical property change region of the medical elongated body which has a relatively large change in physical property. A tubular member forming a second region of a distal member of a medical elongated body is integrally formed with a shaft portion. The distal member has a reinforcement layer containing a metallic material and formed between an inner layer and an outer layer from a first region to the second region. The reinforcement layer is disposed inside the tubular member in the second region. An outer diameter of the first region is set smaller than an outer diameter of the second region.
