Provided is a radio frequency identification (RFID) reader in which a mobile terminal is mounted. The RFID reader comprise a reader body; an RFID reading portion which forms a front of the reader body and includes an RFID module which reads information in an RFID tag by being placed close to the RFID tag; a pocket portion which is connected to a top of the reader body and includes a connection terminal portion which is connectable with a terminal portion of the mobile terminal and is formed on an inner side of the pocket portion; a grip portion which is connected to the reader body in a rear of the RFID reading portion, supports the reader body and to which a switching unit that selectively turns of and off operation of the RFID module is connected; and a control unit which outputs the information of the RFID tag read by the RFID module to the mobile terminal according to operation of the switching unit. According to the present invention, an RFID reader can be used while a mobile terminal such as a PDA is mounted in it, have an effective structure, and also be portable and easy to use.