[Solution] This system is a computer-based system that analyzes the bloodflow at a target blood vessel location of a test subject by means of a computer simulation and that has: a 3D shape extraction unit that reads a captured image at the target blood vessel location and generates 3D shape data of the lumen of the target blood vessel location； a fluid analysis unit that imposes boundary conditions relating to bloodflow to the 3D shape data, and determines state quantities (pressure and flow speed) of the bloodflow at each position of the lumen at the target blood vessel location by means of computation； and a bloodflow characteristic determination unit that, from the state quantities of the bloodflow determined by the fluid analysis unit, determines the wall surface shear stress vector at each position of the blood vessel wall surface of the target blood vessel location, determines the relative relationship between the direction of the wall surface shear stress vector at a specific wall surface position and the direction of the wall surface shear stress vector at wall surface positions at the periphery thereof, and from the form thereof, determines the characteristics of the bloodflow at the wall surface position and outputs same as determination results.
