1. An interactive graphic editing system for designing a semiconductor integrated circuit comprising: an attribute data base storage unit in which attributes of various editing objects necessary for simulating characteristics of the semiconductor integrated circuit being designed are stored, and editing means for enabling the editing objects to be manipulated and for fetching data from the attribute data base storage unit on selection of the editing objects to determine whether or not the attributes for the selected editing objects can be set and, if the attributes can be set, allowing a user to select attributes for the editing objects.