Disclosed is a link connection structure of an operation pedal for vehicle wherein rolling caulking is performed at the tip portion of connection pins (38, 40) under such a state as the shaft portion (44) of the connection pins are penetrating the connection portions (34, 36) when an operation pedal (14) and a rotary member (18) are connected by connection links (20a, 20b), and since plastic deformation takes place to form a predetermined gap ? between the connection portions (34, 36) and a locking portion (46) is formed by increasing the diameter at the tip portion, relative rotation of the connection portions (34, 36) is permitted because there is a gap ? on contrary to conventional ordinary caulking. Consequently, the locking process, i.e. the rolling caulking process, of the connection pins (38, 40) can be easily performed automatically and since a locking member such as an E-ring is not required nor the grooving for attaching the locking member to the shaft portion (44) of the connection pins (38, 40) is required, the link connection structure can be constituted inexpensively of a small number of components.