PROBLEM TO BE SOLVED: To provide a joint structure in which joint strength is further improved including improvement of joint strength with respect to pressure in a radial direction, and a catheter having the joint structure. In a joining structure of a tubular member 3 made of resin and a tubular member 5 made of resin, a joining surface of the tubular member 3 and the tubular member 5 has an uneven shape in a major axis direction along a circumferential direction. In the cross-sectional view, either one of the tubular member 3 and the tubular member 5 is formed so as to enter the other tubular member in a region other than both ends of the other tubular member. [Selection] Figure 2【課題】 放射方向の圧力に対する接合強度の向上を含めてさらに接合強度を向上させた接合構造及びその接合構造を有するカテーテルを提供する。【解決手段】 樹脂からなる管状部材３と樹脂からなる管状部材５との接合構造において、管状部材３と管状部材５との接合面は、円周方向に沿って長軸方向に凸凹形状を呈しており、断面視において、管状部材３及び管状部材５の何れか一方の管状部材が、他方の管状部材に、その他方の管状部材の両端以外の領域において入り込むように形成されている。【選択図】図２
