1. A method for displaying executing circumstances of a program comprising the steps of: (a) storing in store means a program constituted from a plurality of program elements; (b) reading the program from the store means and converting each program element thereof into a graphic element corresponding to said each program element, thereby displaying a schema of the program on a display in graphs; (c) executing the program; (d) monitoring the executing circumstances of the program; and, (e) classifying into a plurality of kinds of executing circumstances each program element in a path of execution of the program and displaying according to the classification of the executing circumstances the graphic elements of said program elements in a visually discriminated fashion in a realtime fashion during the program execution.