A method of registering phone book data, group-by-group, in a mobile communication terminal comprising a memory, a controller and a display unit, the method comprising: - the controller determining that a phone book data display request is input by a user; - the controller displaying a plurality of groups of phone book data stored in the memory on the display unit and selecting a group among the groups displayed on the display unit in response to a first user selection information; - the controller further determining that a phone book data movement request is input by the user, reading phone book data stored in the selected group from the memory, displaying the read phone book data on the display unit and selecting at least one of the phone book data displayed on the display unit in response to a second user selection information; - the controller, after determining that the phone book data selection is completed, determining whether a group creation request is input by the user by displaying an image on the display unit for asking the user to select whether a new group is to be created; - if the group creation request is not input by the user, the controller further displaying on the display unit the groups of phone book data stored in the memory, assigning a group where the selected phone book data is to be moved in response to a third user selection information and moving and storing the selected phone book data into the assigned group; - if the group creation request is input by the user, the controller further requesting the user to input the name of a group to be created, creating a group having the input group name and moving and storing the selected phone book data into the created group. - the controller determining that a phone book data display request is input by a user; - the controller displaying a plurality of groups of phone book data stored in the memory on the display unit and selecting a group among the groups displayed on the display unit in response to a first user selection information; - the controller further determining that a phone book data movement request is input by the user, reading phone book data stored in the selected group from the memory, displaying the read phone book data on the display unit and selecting at least one of the phone book data displayed on the display unit in response to a second user selection information; - the controller, after determining that the phone book data selection is completed, determining whether a group creation request is input by the user by displaying an image on the display unit for asking the user to select whether a new group is to be created; - if the group creation request is not input by the user, the controller further displaying on the display unit the groups of phone book data stored in the memory, assigning a group where the selected phone book data is to be moved in response to a third user selection information and moving and storing the selected phone book data into the assigned group; - if the group creation request is input by the user, the controller further requesting the user to input the name of a group to be created, creating a group having the input group name and moving and storing the selected phone book data into the created group.