An electrical connector for electrically connecting an integrated circuit package to a circuit substrate includes a first and a second unit sections, and each unit section has a number of terminals received therein. Each unit section includes a mating surface, an opposed mounting surface, a fixing edge, and an engaging edge. The engaging edge of the first unit section has a protruding tongue, and the engaging edge of the second unit section defines a recessed portion for engaging the protruding tongue. An interlocking device is formed between the protruding tongue and the recessed portion, so that the protruding tongue is capable of overlapping and combined with the recessed portion via the interlocking device to make the first and the second unit sections become a unitary structure.