A SDS PAGE technique is adopted to investigate the change of membrane cytoskeleton protein for hereditary spherocytosis(HS).The membrane vicoelastic properties are determined by the micropipette aspiration technique.The results show that the membrane elastic modulus of HS erythrocyte hase no remarkable difference but the viscosity is significantly higher than normal cells and the deformability of HS erythrocyte is reduced.It is discovered that spectrin,band 3 and band 5 of HS erythrocyte are partly deficient;the membrane thiol groups concentration of HS erythrocyte is lower than normal cells.These results suggest that the integrity of the struture and ingredient of the cytoskeleton protein networks plays an important role in deformability of erythrocvte.