An RFID cargo/storage container tamper seal consisting of a main insulating body, a locking rod and a circuit module is disclosed. The main insulating body has a helix-shaped antenna and a ring-shaped metal ring, wherein the inner surface of the metal ring has a C-shaped ring inlaid therein, and the antenna has an antenna probe extending and protruding from the metal ring. A first portion of the locking rod is cone-shaped and encapsulated by an insulating material, and a second portion thereof exposed from the insulating material has a ring-shaped groove disposed around its peripheral surfaces. The circuit module has an RFID chip embedded therein and is packaged inside the rod portion, thereby allowing an RFID reader to read electromagnetic waves/signals containing identification codes transmitted from the RFID chip of the RFID tamper seal via the antenna.