A memory card includes a control chip, a buffer, a NAND gate, and an inverter. The memory card has a first surface and a second surface opposite to the first surface. A first group of conductive pins is located on the first surface, and connected to the buffer through a first channel. A second group of conductive pins is located on the second surface, and connected to the buffer through a second channel. An order of pins of the first group of conductive pins located on the first surface from left to right is the same as an order of pins of the second group of conductive pins located on the second. The buffer is electrically connected to the control chip. Data can be transmitted between the first group of conductive pins or the second group of conductive pins and the control chip through the buffer.