[Problem] Provided is a junction structure in which the joining strength is further improved by adding an improved joining strength against a pressure in the radial direction, and a catheter having the junction structure.[Solution] Provided is a junction structure between the tubular member 3 made of resin and the tubular member 5 made of resin, in which an interface between the tubular member 3 and the tubular member 5 has an uneven shape in the long axis direction along the circumferential direction, and any one of the tubular member 3 and the tubular member 5 is configured to enter into the other tubular member at a region other than the both edges of the other tubular member in a cross sectional view.
