A grading system includes a server computer installed in a management company and a client computer owned by a client and connected to the server computer via a network. Through a scanner etc., the client computer reads the condition information of the card and transmits the information to the server computer. The server computer appraises the card and transmit an appraisal result to the client computer. The client computer registers the appraisal result in the card. The client computer reads the card information stored in the card on demand and transmits the information to the server computer connected to the network. The server computer updates the card information via the network. The server computer intermediates the card trading (the transfer of a card and the accounting procedure).

In a trading card, a famous athlete's photograph is printed on a substrate of, for example, paper or plastic. The trading card has a signing portion and a seal portion. An IC chip is mounted in the trading card. An autograph is signed in the signing portion, and a seal is affixed in the seal portion. The signing portion and the seal portion are surface-treated; e.g., by means of increasing the surface friction, so that clear signing and seal affixing can be performed. The seal has a seal profile representing a character or a symbol relating to an athlete, preferably unique to him or her; e.g., the athlete's name, uniform number, or motto, etc.

A grading system includes a sever computer installed in a management company and a client computer owned by a client and connected to the server computer via a network. Through use of the client computer, a client requests the sever computer to appraise and register a card. The management company appraises the card received from the client and stores an appraisal result and information regarding the client in an IC chip as card information. Subsequently, the management company returns the card and the IC chip to the client.