Abstract: A system for applying RFID in ball game field to assist in making a decision in ball game includes a RFID tagging element embedded in a ball used in the game; a plurality of RFID reading devices spaced along borderlines of the ball game field for reading the RFID tagging element in the ball; and a control center connected to the RFID reading devices. When the ball with embedded RFID tagging element touches any of the borderlines, at least one of the RFID reading devices reads the RFID tagging element and sends a signal to the control center for determining whether the ball is out of bound or not. When the RFID reading devices are arranged at goal areas, the system may be used to determine the scoring. A decision signal is sent from the control center to a referee for use as a reference in making a decision.