Connector connectable to coaxial cable without using tool is disclosed. The connector comprises an outer sleeve including a front inward rim and a staged bore; an inner sleeve including a front flange and a front inward rim; a nut; a cylindrical coupling sleeved on the outer sleeve; and a resilient gripping ring. A rear inward rim of the nut is fitted between the outer sleeve and the flange and is sleeved on the inner sleeve. The rim of the outer sleeve is sleeved on the inner sleeve. The ring is sandwiched between a rear inward rim of the coupling and the inner sleeve. The cable is inserted into the coupling and the ring for fitting the outer insulator in the inner sleeve. The insertion is stopped as the outer insulator of the cable contacts the rim of the inner sleeve. The cable is fastened in the connector by the ring.