A cable assembly includes an insulation housing, a plurality of contacts, a plurality of wires and a spacer. The housing includes a mating portion, a pair of flat portions extending from two sides of the mating portion, and a receiving space formed between the two flat portions. Each of the contacts is received in the housing and has a rear surface. The wires are corresponding to the contacts and each wire is connected its corresponding contact. The spacer is attached to the housing and has a front surface attached to the rear surface of the contact. The spacer includes a plurality of slots received in the receiving space. And the wires are respectively received in the slots.