A dustproof receptacle connector includes a dielectric housing, a plurality of terminals, a shield and a dustproof cover. The dielectric housing defines a plurality of terminal grooves therein for receiving the terminals. The shield surrounding the dielectric housing has a top board. A sliding groove is defined in the top board and extends longitudinally to pass through a rear end of the top board. An engaging portion extends from the rear end of the top board. A receiving groove is surrounded by the engaging portion and the rear end of the top board and communicates with the sliding groove. The engaging portion is bent downward to be attached to a rear portion of the dielectric housing. The dustproof cover is slidably received in the shield and located between the dielectric housing and a front end of the shield. The dustproof cover has a positioning portion slidable along the sliding groove.