A socket connector is provided for accommodating different sizes of chips and a printed circuit board and includes an insulative housing and a plurality of contacts embedded in the housing. The housing includes a conductive region and a margin region around the conductive region, and defines a supporting surface and a mounting surface opposite to the supporting surface. A number of passageways for accommodated the contacts extending through the isulative housing. Sidewalls extend upwardly from the margin region with a plurality of location blocks extending to the conductive region. The location blocks and the sidewalls are unitarily formed. A number of engaging grooves are defined in the margin region for assembling a number of aligning keys can be assembled to the respond engaging grooves for accommodating different sizes of chips.