Provided is an electrical connector including an insulative housing defining a plurality of terminal grooves therein and a plurality of terminals received in said terminal grooves. The terminals comprise a plurality of first terminal groups and second terminal groups which are configured as a same structure and alternatively arranged. Each of said first and second terminal groups comprises at least a base portion and an opening portion thereon. The base portion of the first terminal group faces to the opening portion of the neighboring second terminal group, while the opening portion of the first terminal group faces to the base portion of the neighboring second terminal group.