Abstract: This paper proposed a T-Y tube model to simulate foe input impedance of arterial system. It improves and extends the asymmetric T-tube model which was firstproposed by O'Rourke^[1] and developed laier by Liu et al.^[2]. Based on foe asymmetricT-tube model. a T-Y tube model was proposed by adding branching tubes which represem the iliac arteries.All the tubes are considered to be uniform,viscoelastic longitudinally tethered cylindrical tubes.The upper tube terminates with a windkessel model, while the terminal arterioles of the lowr tube are expressed as a resistance.After proper eraluation of the parameters.the impedance of the arterial system iscalculated under normal physiological and hypertensive condition.The model canpredict impedance in good agreement with the experimentally obtained data no matterin normal physiological condition or in pathological condition In comparison with theasymmeric T-tube model,T-Y tube model is closer to anatomy structure of the human arlerial system and at the sametime much simpler than the extremely complex multiple-branching tube model Therefore it will be a valuable model in studying the influences of various parameters on aorta impedance and ventricular-vascular coupling.