When intact red blood cells were irradiated with ,γ-, ray and subsequently incubated for 4 and 6 h at 37℃, an increase in radiation haemolysis was observed with increasing dose. Irradiation, especially at 2×10,3, Gy, resulted in a 94.1%haemolysis. When 2.5×10,-3,mol/L PABGA was added to the irradiated samples, haemolysis was inhibited. It indicated that haemolysis was mainly due to the effect of OH. radicals on erythrocyte membrane. The γ-irradiation effect of intact blood cells and erythrocyte membrane was different. γ-irradiation can induce formation of protein cross-linking of erythrocyte membrane, but not the cross-linking of the red blood cell membranes. Formation of lipofuscin after irradiation was observed in the erythrocyte membrane and red blood cells.In the case of erythrocyte membrane there was a greater change in protein SH groups and lipid peroxdiation than in the case of intact red blood cells.