An electric connector includes a connector body having contact terminals mounted in a first end thereof and an axial through hole axially formed in a second end thereof opposite to the first end. A power cable is inserted into the axial through hole of the connector body and electrically connected to the contact terminals. Two retaining members are transversely mounted in the connector body and engaged at two opposite sides of the power cable to hold the power cable in the axial through hole of the connector body. The retaining members are movable relative to each other to adjust a pitch therebetween subject to a diameter of the power cable.