Rf-id tag reading system for using password and method thereof

The RF-ID tag with enhanced security is provided. The tag group when the set password information and tag data, the tag is stored a memory unit, an antenna unit for receiving a transmission request signal for the tag data from the external reader (Reader), and, a transmission request signal is received the password transmitted to the reader If after, the password is transmitted from the reader and the preset password match requested and a tag control unit for transmitting the tag data. Accordingly, it is possible to have other users do not know the password preventing check the tag data. RF-ID tag, the tag data, the password, RF-ID reader