Abstract: A stop valve includes a valve body having a receiving space, a shaft rotatably mounted in the receiving space of the valve body, and an operation member mounted on the shaft. The shaft has a shaft body and a driven portion. The shaft body is provided with a connecting hole. The shaft body has a periphery provided with two retaining grooves for mounting two seal rings. The two seal rings are directly formed in the two retaining grooves of the shaft body in a secondary molding mode so that the two seal rings and the two retaining grooves of the shaft body have greater strength of combination, such that the two seal rings will not be detached from the two retaining grooves of the shaft body, thereby preventing from incurring fluid leakage.