A plug and socket convertible electrical connector assembly including a connector body and a slide cover is disclosed. The connector body includes a housing defining an oblong insertion opening and multiple insertion slots at two adjacent walls thereof, a rack mounted in the housing, an electrical socket mounted in the rack and aimed at the insertion opening. The slide cover carrying multiple metal conducting blades is mounted in the housing and movable between a received position where the insertion opening is opened for allowing insertion of an external power adapter cable into the electrical socket, and an extended position where the slide cover blocks the insertion opening and the metal conducting blades are extended out of the insertion slots for connection to a city power supply outlet.