Numerical simulations are important tools for understanding the human circulation system in different states of heart failure and exercise, or with a cardiac assist device. However, its application is limited due to the complexity of the numerical model of the human circulation system. To overcome this difficulty, a Graphic User Interface (GUI) has been developed. The GUI was designed to be intuitive; users can set different scenarios using self-explanatory controls, without knowledge of the tasks done in the complex numerical model. The GUI will display the simulated hemodynamic response of the model. This GUI may be used for both education and medical/research purposes.