Abstract: A memory card adapter is disclosed to include a connecting substrate with metal contacts, a multi-in-one memory card connector bonded to the connecting substrate for receiving one of a set of memory cards, a connecting terminal set, which has a plurality of metal terminals mounted in an electrically insulative terminal holder block with a rear bonding end of each metal terminal respectively bonded to the metal contacts of the connecting substrate and a front bonding ends for bonding to a PC board, a PC board, which has an electric connector at one end for connection to a notebook computer or the like and a plurality of metal contacts respectively bonded to the front bonding ends of the metal terminals of the connecting terminal set, and an electrically insulative housing, which has a rectangular frame that accommodates the connecting substrate and the PC board and two cover shells respectively covered on top and bottom sides of the rectangular frame over the connecting substrate and the PC board.