The electronic tag of the present invention is mounted under the door holder on the front and right side of the container and the lock bolt on the electronic tag is inserted into the holes of the container door handle and the door seal turnover panel. The lock cap screws to the lock bolt tightly, so that the lock bolt can not be pulled out from the electronic tag. The electronic tag adopts RFID technique, GPS satellite positing and identifying technique and un-touching approach switch door seal technique. When the lock cap screws onto the lock bolt, the door closing information is recorded; when the lock cap screws out from the lock bolt, the door opening information is recorded. The present invention identifies, reads and writes the freight information, logistics information, door seal information of the container through the electronic tag in an un-touching manner. The electronic tag has large storage volume, long life span, and good security. Besides, the electronic tag also has GPS that can position and identify the position of the container.