Objective Through controlling the liquid capacity and liquid resistance in an apparatus of endothelial cells' shear stress testing to simulate a physiological condition of the body for endothelial cells. Methods Bases on the hydrodynamics and hemodynamics theories, the liquid capacity and liquid resistance were calculated. Results This apparatus can clearly simulate hemodynamic environment coincided with the physiological condition of the body and regulate the values of the shear stress, vertical stress and pulsatile amplitude ,pulsatile frequency of the vertical stress. Conclusion The liquid capacity and liquid resistance in testing apparatus of endothelial cells' shear stress can simulate a fidelity physiological condition of the body for endothelial cells.