We have tried to simulate the aortic valve deformation by considering the reflection of blood flow. The aortic valve opens and closes according to blood flow caused by pressure difference between the heart and the aorta. The aortic valve is elastic body while blood is fluid so that two different types of methods are usually used for the simulation; however, it is difficult to calculate collision detection and force between two different types of models. Then, in this paper, both materials are modeled with particles so that collision detection and force between two different types of models can be easily calculated. In addition, by considering the reflection of blood flow at the end of blood vessel, we have succeeded to simulate the deformation of the aortic valve and found that blood flows differently depending on the length of the aortic valve.