Provided is a junction structure between a first tubular member and a second tubular member, and a catheter including the junction structure. An interface between the first tubular member and the second tubular member has an uneven shape in the longitudinal direction of the junction structure along a circumferential direction of the first tubular member and the second tubular member. At least one of the first tubular member and the second tubular member includes a protruding portion that protrudes into the other tubular member only between an inner periphery of the other tubular member and an outer periphery of the other tubular member. The joining strength of the junction structure is improved against a pressure in the radial direction.
