符牌制度起源甚早,其完善于唐代,以后各代相袭沿用,成为国家重要典章制度之一。春秋战国时期出现虎符,作为传达命令或调兵遣将的凭证,使用时双方各执一半合之以验真伪。隋唐之后出现鱼符、龟符等,除用作传达命令、调动军马外,还用作出入宫禁的凭证。宋、辽、金、元诸朝,皆借鉴唐制,加以改进后形成自己的符牌制度。 Symbol system originated very early, and its perfection in the Tang Dynasty, followed by generations of attack, becoming one of the important state rules and regulations. During the Spring and Autumn and the Warring States period, tiger symbols appeared as a voucher to convey orders or troop movements. When both parties took part, they were united to verify the authenticity. Sui and Tang emerged after the fish, Turtle Fu, etc., in addition to communicating orders, mobilizing troops and horses, but also used as evidence of access to the palace. Song, Liao, Jin, Yuan dynasties, all learn from the Tang system, to be improved to form their own licensing system.