Magnetic moments of single micrometer particles were measured in high gradient magnetic separation (HGMS) analysis. HGMS-method showed the concentrating process of macromolecules of nucleoprotein, ferritin, red blood cells. Magnetic force acting on single micron and submicron biological particles having diamagnetic or paramagnetic susceptibility in respect to solution caused their movement and accumulation in gradient magnetic fields in dependence on magnetic moment values. Methods developed in study allowed obtaining magnetic moments of single particles and average values from magnetic separation parameters.