Abstract: Objective To examine the relationship between the change of erythrocyte immune state and the leves of SOD and LPO in smoking people.Methods One hundred and fifty-eight healthy adult men were divided into two groups:smoking group (116 cases)and non-smoking control group(42 cases).Plasma red blood cell C3B receptor(RBC-C3bRR),red cell blood immune complex resette(RBC-ICR),superoxide dismutase(SOD)and lipid peroxide(LPO)were determined in the two groups.Results RBC-C3bRR and SOD in the smoking group were markedly lower compared with those of the non-smoking group(P<0.01,P <0.05),while RBC-ICR and LPO were significantly increased (P<0.01).Furthermore,the correlation analysis showed that there was a significantly negatively correlation between SOD and the smoking quantity(r=-0.0584,P<0.05),which is a signifcantly positive correlation between serum LPO and the smoking quantity(r=0.828,P<0.01).In addition,the RBC-C3bRR was related positively to SOD(r=0.785,P<0.01),but negatively to LPO(r=-0.913,P<0.01).Conclusion Erthrocyte immune in smoking people is decreased,which is in relation to the decrease of erythrocyte SOD and the increase of LPO.