In this study,a new method to evaluate erythrocyte deformability by measurements of erythrocyte sedimentation process,introduced by authors,was adopted to investigate the deformability of swine erythrocytes in a physiological saline solution and in a SF60 solution. Experimental results indicated that the deformability factors are .0. 862 and 0. 971 for erythrocytes suspended in a physiological saline solution and in a SF60 solution.respectively.