The present invention relates to a card reader having communicating function which includes: a top cover; a bottom cover having a first open slot at one side; a printed circuit board; a first memory insertion slot allowing a first removable memory card to be inserted; a processor for controlling the access of first removable memory card; a wireless communication module; a card reader controller; a connector; a charging circuit; a rechargeable battery; and a voltage regulation circuit; such that a portable electronic device is able to access the data in the first removable memory card with a wireless means, or a mainframe is able to access the data in the first removable memory card through the connector.