My task is to create a Graphical User Interface (GUI) to a diabetes simulator. At the simulator’s input we can import diabetes patients’ records which conatin inter alia their bloodsugar level’s alternation in time and the input carbohydrate amount - which can be seen as a disturbance on the input - and we can select the meal absortion model. We’ll be able to choose from several diabetes models, and we can connect three controllers on the selected one, each with an observer. We can modify each of the elements’ settings, we can reach each of the elements’ documentations from the GUI as well and we can invoke their simulink model with a desired buttonpush. After running a simulation the results can be displayed and saved numerically and graphically. All the functions will be available also from the menubar, and some of them can be accessed only from here (e.g. Undo/Redo), and we can follow the ongoing processes in a status bar. There will be a chance to change the simulator’s language (between Hungarian and English at first).