Abstract: Objective Aims researches on the interaction between heart valves is limited in clinical. Meanwhile the data of in vitro testing are insufficient. In this study, the in vitro hydrodynamic performance of an aortic valve was studied by using a model of mitral regurgitation that could finely adjust the regurgitant volume. Methods The regurgitation of mitral valve was gradually increased under the certain condition of heart rate, stroke volume, and mean aortic pressure and captured the hydrodynamic performance of the aortic valve. Results The study on the hydrodynamic performance of mechanical aortic valve (25AJ-501) by using a model of mitral regurgitation found that the effective orifice area and mean pressure difference of the aortic valve are negatively correlated with the degree of mitral regurgitation. Conclusion The method based on a model of mitral regurgitation that could finely adjust the regurgitant volume established in this study can be used to study the effect of mitral valve regurgitation on the hydrodynamic performance of the aortic valve.