A card assembly is used for enabling a first electronic device to be compatible with a card used in a second electronic device. The card assembly defines a first group of specification parameters of the first electronic device to be detachable received in the first electronic device, and further defines a second group of specification parameters of the card. The second group of specification parameters allows the card to be detachable received in the card assembly. When the card assembly, with the card, is received in the first electronic device, the card is directly and electrically connected to the first electronic device.