Objective To set up a novel hemodynamics distributing-parameter model with posture change and study the effect of gravity on pressure of blood flow in a singular vessel.Method To simulate the effect of gravity on pressure of blood flow with different postures by introducing a volume-related force into the conventional hemodynamics model.Result The procedures that gravity affects pressure of blood flow are different due to discriminating postures.Conclusion The novel model established in this study is capable of simulating the effect of posture on pressure of blood flow, which is helpful for our further investigation into the effect of posture on cardiovascular indexes.