An electrical receptacle connector includes an insulated housing, conductive terminals, and a fixing base. The insulated housing defines a connecting space therein. The insulated housing includes a tongue portion extending into the connecting space and a base portion arranged at the rear part of the tongue portion. The base portion has a rear wall, two lateral walls extended backward from the rear wall, and an assembling space defined by the rear wall and the two lateral walls. The fixing base is received in the assembling space and defines first through holes and second through holes. The pins of the conductive terminals are passing through the first through holes and the second through holes. The fixing base has a rear wall surface defining grooves communicating with the respective first through holes. The width of the groove is less than the width of the corresponding first through hole.