Abstract: Provided is a payment processing system and a method thereof employing an off-line transaction approval mode of a mobile card. Card information and off-line transaction approval information is contained in a mobile device such as a cellular phone which us used as a mobile card. A server in a card issuing company computer center registers a Black List (B/L) on a corresponding card of the mobile device through an On-The-Air (OTA) function at the time when a Black List (B/L) item occurs. Accordingly, the mobile device confirms whether or not the card is included in the Black List (B/L) at the time of using the card for transactions. The mobile device communicates with a card reader in a card affiliated shop only when the card can be used for payment of transactions.