The cause of red cell aggregation is because the Constitution in the acidification of the, asymmetric proteins in blood increases, the molecules that affect red blood cells of the electrostatic properties, resulting in reduction of surface charge, causing cells lose the repulsive force, and chitosan oligosaccharide by virtue of its positive charge characteristics can change the cell pressure difference between the inside and outside (blood rheology, thereby increasing the repulsive force between cells and get rid of the purpose of the gathering.