A system for providing banking services by use of a mobile communication system, in which a variety of financial transactions including inquiry of at least one financial account of at least one financial institution, transfer and remittance, and loan and its interest payment are processed by the mobile communication system. The system includes: the mobile communication system, provided with an integrated circuit (IC) card and a memory device to which a banking application is installed, for transmitting and receiving data by wireless, the IC card being stored with information on a personal identification number (PIN) and information related to financial accounts including a loan account. The banking application processing the financial transactions including the financial account inquiry, the transfer and remittance, and the loan and its interest payment by mobile banking; a base station transceiver system (BTS) for executing a wireless interface with the mobile communication system and a base station controller (BSC) for performing call processing and for providing a core network interface with the BTS. A packet data switching network (PDSN) for providing a packet data transfer service using a transmission control protocol / Internet protocol (TCP / IP); and at least one banking server for, when being requested to process the financial transactions including the financial transactions including the financial account inquiry, the transfer and remittance, and the loan and its interest payment by the banking application of the mobile communication system.