A cable connector assembly which reduces a cross sectional area of an end portion of a cable and which can be conveniently and securely assembled to a connector, comprises a main body, a cable and a clamp device. The main body has a connecting portion receiving a number of terminals for electrically connecting with a mating connector at one end and a receiving space accommodating a housing block. The cable has an electrical portion at an end portion thereof for electrically connecting with the terminals of the connecting portion. The clamp device comprising at least two clamping portions and fixing portions corresponding to the housing block is received in the receiving space and assembled to the housing block. Thus the end portion of the cable is deformed and retained by the clamping portions and secured to the housing block by the fixing portions of the clamp device.