Abstract: A method of inputting an address book into a mobile communication terminal including the steps of inputting, from the mobile communication terminal, an address book service number including a characteristic number allocated to a client who wants address book information to be provided, to an address book management center to supply and request the address book information; transmitting the address book service number to the address book management center; receiving the address book service number at the address book management center; searching in the address book management center for the address book information corresponding to the characteristic number; transmitting the retrieved address book information to the mobile communication terminal; and storing in the mobile communication terminal the received address book information.