Abstract: A passive transponder identification system and credit card type transponder are disclosed, particularly, the transponder identification system to utilize a transmitting manner of two different RF signals is provided. The present invention directly relates to a passive transponder without any kind of power source. Therefore, the present invention has advantages of having a constant gain value by developing a high-gain dual polarizing antenna for a small credit card type passive transponder to identify at long distance, independently to any direction of the transponder; improving gain values than conventional transponder tag antenna by 6-9 dB to ensure a sub-permanent life time by providing the desired identification performance by a small credit card type passive transponder without power supply; and being applicable to any systems to identify and distinguish high-speed moving objects.