Abstract: Provided is a balloon for a balloon catheter that can suppress circumferential fracture by generating longitudinal axial fracture in the central part of the balloon, and prevent the fracture in the longitudinal axis direction from extending to the proximal or distal side of the balloon to form a L-shaped crack by keeping the longitudinal fracture within the straight tubular part. A balloon (2) for a balloon catheter has a main orientation direction of the molecular orientation in a proximal section (23a) and a distal section (23e) of a straight tubular part (23) is the circumferential direction z, and a component of the molecular orientation in the longitudinal axis direction x in the central section (23c) of the straight tubular part (23) is more than a component in the longitudinal axis direction x in the proximal section (23a) and the distal section (23e) of the straight tubular part (23).