Abstract: A method and system for providing a card payment using a mobile phone number. A service server receives a payment request from an affiliate system through a wired/wireless data network, the payment request being inputted through a user terminal and including a mobile phone number of a mobile terminal of a user. A telephone call is connected to the mobile terminal using the mobile phone number included in the received payment request. When the telephone call is connected, an input of a service password is requesting through the connected telephone call. When a service password received through the telephone call from the mobile terminal is identical to a service password stored in the service server, a payment authentication process is performed using a virtual card number generated by the service server, the virtual card number being mapped to a card matching the mobile phone number.