A credit card signature inspection system includes a card-sliding device and a credit card server. The card-sliding device produces a signature authentication request including credit card data and produces a bill to be signed. The credit card server includes a credit card database pre-stored with data of credit cards. Data of each credit card corresponds to an authentication signature of a credit card holder. The credit card server receives the signature authentication request and searches the credit card database based on the credit card data in the signature authentication request to produce an authentication signature corresponding to the credit card data. The authentication signature is transferred to the card-sliding device and displayed on the card-sliding device to check whether the authentication signature on the card-sliding device corresponds to the signature of the consumer for the bill, so as to determine whether to approve the proceeding of the transaction.