We developed a valve hybrid fractal stent to treat the cerebral aneurysm what is one of a cerebrovascular disease. The stent has a valve part to path through a coil. The valves have fractal structures. So, the blood flowing into cerebral aneurysm is prevented. We performed a Particle Image Velocimetry (PIV) experiment to evaluate the inflow into cerebral aneurysm. By the experiment result, we visualized the stream line by using the cerebral aneurysm. By calculation, we succeeded in a reduction in the inflow by using the valve fractal stent.