Objective Clinical research,animal and simulation experiments have revealed that the myocardial bridge presses mural coronary artery,which leads to the changes of the rate of flow and pressures of mural coronary artery, and results in special homodynamic phenomenon.This paper discusses the mechanism of this phenomenon in the proximal part of the myocardial bridge using water hammer theory.Methods The hemodynamical characteristics of mural coronary artery were simulated using a simulated apparatus.The pressures and velocities in the proximal part of the myocardial bridge were measured in middle of systole and at the beginning of diastole.One-dimensional water hammer theory was used and compared with the data of experiments.Results Theoretical elevates of systolic pressures and diastolic velocities of the mural coronary artery basically agree with the data of measurements.Conclusion The mechanical mechanism of special phenomenon of mural coronary artery can be explained using water hammer theory.