A RFID system applying to a three-dimensional jigsaw is provided. The RFID system includes a jigsaw substrate having a plurality of blocks, a plurality of jigsaw units corresponding to each blocks of the jigsaw substrate, a RFID reader having a plurality of antennas positioned in a position of each blocks of the jigsaw substrate, and a plurality of tags positioned in a position of each face of a three-dimensional jigsaw unit corresponding to the positions of the antennas, wherein the RFID reader communicates to the tags using modulated radio signals through the antennas and the tags respond with modulated radio signals in order to determine whether the orientation of the three-dimensional jigsaw unit is correct or not.