A multimedia playing system, an apparatus for identifying a file, and a method thereof are provided. The multimedia playing system comprises a display device, a sensing device, and an identification device. The display device is configured to display the file and has a predetermined area. A plurality of color tags adapted to be displayed on the predetermined area is attached to the file. The sensing device continuously senses the predetermined area to generate a sensed datum. The identification device is connected to the sensing device and receives the sensed data from the sensing device to determine a sensed color code representing each of the sensed data. The identification device further forms a sensed sequence by the sensed color codes and determines a piece of display information corresponding to the sensed sequence.