The invention relates to an enhanced mechanism for RFID reader which includes: an antenna for receiving a RFID signal transmitted from an object under test and outputting the RFID signal to the RFID reader; a metal plate disposed on an entrance of a building. The metal plate and the object under test are respectively placed on opposite sides of the antenna. The angle between the first metal plate and the second metal plate is from 30 to 180 degrees; therefore the metal plate, the antenna, and the RFID reader provide an enhanced mechanism of a RFID reader.