The present invention provides a method for producing an additive for an erythrocyte concentrate that is highly effective in inhibiting hemolysis and offers excellent erythrocyte storability, the method comprising: mixing a surfactant, for which the HLB value is 10 or higher and the hydrophilic moiety in the molecular structure is a polyoxyethylene and/or polyoxyethylene sorbitan having 20 or more oxyethylene groups, and vitamin E in a range of 1:1 to 1:2.5 by volume in an erythrocyte storage solution and sterilizing the mixture by heating under conditions where displacement of the center position of a peak top of the mixture of the erythrocyte storage solution, the surfactant, and the vitamin E after sterilization by heating is ±4% or less, as obtained from fluorescence spectra contour data of the mixture before sterilization by heating. Herein, the displacement of the center position of the peak top is measured by the displacement in the excitation wavelength, and is calculated using the following formula: (Center position (nm) of the peak top of the mixture after sterilization by heating - Center position (nm) of the peak top of the mixture before sterilization by heating)/(Center position (nm) of the peak top of the mixture before sterilization by heating) × 100 (%).La présente invention concerne un procédé de production dun additif pour un concentré dérythrocyte qui est hautement efficace dans linhibition dhémolyse et a une excellente capacité de stockage dérythrocyte, le procédé consistant à : mélanger un agent tensio-actif, pour lequel la valeur HLB est de 10 ou plus, et la fraction hydrophile dans la structure moléculaire est un polyoxyéthylène et/ou un polyoxyéthylène sorbitane ayant 20 groupes doxyéthylène ou plus, et une vitamine E dans une plage de 1:1 à 1:2,5 par volume dans une solution de stockage dérythrocyte et stériliser le mélange en chauffant dans des conditions où le déplacement de la position centrale dun sommet de pic du mélange de la solutio
