An electrical connector has a insulative housing defining a plurality of passageways and a plurality of contacts secured in the passageways. Each passageway has a mating slot and a pair of retaining slots located at two sides of the mating slot and communicated with the mating slot. Each contact defines a soldering tail and a pair of arm portions extending from the soldering tail and retained in the two retaining slots respectively, the pair of arm portions shift in and between the mating slot and the retaining slot in a first direction, a pair of contact portions integrally project oppositely from inner sides of the arm portions. Wherein the arm portions define shrink sections at a position thereof opposite to the contact portions so that the shrink sections space away from the retaining slots in a second direction perpendicular to the first direction. It can reduce inserting force and ensure electrical connecting performance of the electrical connector.