Abstract: The invention provides a miniaturized radio frequency identification tag, which comprises a radio frequency identification chip and an antenna. The antenna comprises a plurality of loop antenna line segments. Each of loop antenna line segments is disposed on a corresponding insulating layer, and electrically connected to the radio frequency identification chip or the other loop antenna line segment via a corresponding conductive through hole. Accordingly, the structure of the antenna is fabricated by multi-layer loop antenna line segments so as to reduce the size of the radio frequency identification tag, effectively.