An electrical connector assembly includes an electrical receptacle connector and an electrical plug connector. The electrical receptacle connector includes a first insulation housing, upper-row plate terminals, and lower-row plate terminals. The first insulation housing includes a first base portion and a tongue portion extending from one side of the base portion. The upper-row plate terminals and the lower-row plate terminals are at an upper surface and a lower surface of the tongue portion, respectively. The electrical plug connector includes a second insulation housing, upper-row elastic terminals, and lower-row elastic terminals. The second insulation housing includes a second base portion, an upper member, a lower member, and a mating room between the upper member and the lower member for receiving the tongue portion. The upper-row elastic terminals and the lower-row elastic terminals are respectively above and below the mating room.