Abstract: A graphical user interface (GUI) editing system for developing or editing of a new GUI through a GUI environment provided to a workstation, a personal computer or the like. The system is designed so that user's erroneous operations can be effectively avoided, various sorts of processing are defined for a minimum number of events, the GUI editing can be carried out flexibly under various GUI development environments while not prescribed by the size of GUI elements or by a GUI definition language, whereby such GUI development and editing can be efficiently and flexibly realized on a general-purpose operating system (OS). Further, a denotation procedure of a newly designed or edited GUI developing element to a GUI element database can be remarkably simplified.