The present invention relates to a separation system anda separation material for easily and rapidly separating a redblood cell-rich fraction, a white blood cell-rich fraction,and/or a platelet-rich fraction from a biological fluidcontaining these blood cell components without the necessityof performing centrifugation. The separation of a red bloodcell-rich fraction, a white blood cell-rich fraction, and/ora platelet-rich fraction from a biological fluid can beaccomplished by capturing white blood cells and platelets ona blood cell separation material by contacting the biologicalfluid with the blood cell separation material, therebyproviding a red blood cell-rich fraction； and recovering a whiteblood cell-rich fraction by separating white blood cellscaptured from the resulting blood cell separation materialusing a separation solution.
