Abstract: AIM: To observe and analyze the relationship between anticardiolipin antibody (ACA) and paraoxonase (PON), oxidized low-density lipoprotein (ox-LDL), malondialdehycle (MDA), superoxide dismutase (SOD) in patients with coronary heart disease (CHD). METHODS: ACA and ox-LDL were measured by enzyme-linked immunosorbent assay, MDA by thiobarbiuric acid, SOD by xanthine superoxidase, PON by the method of phenyl acetate in 118 patients with CHD and 68 healthy persons. RESULT: The ACA positive rate of CHD was 24%, which was significantly higher than that of healthy persons (the ACA positive rate was 9%, P<0.05) PON, ox-LDL, MDA, SOD levels were (122±40) kU/L, (0.81±0.26) mg/L, (7.6±1.1) μmol/L and (72±20) μU/ml, respectively, in ACA positive CHD. PON was significantly decreased (P<0.05), ox-LDL and MDA levels were significantly increased (P<0.05), but SOD was not different compared with ACA negative CHD. There was a negative correlation between PON and ox-LDL, MDA by correlation analysis, respectively (r=-0.825, P<0.01; r=-0.735, P<0.01). CONCLUSION: Lipid peroxidation levels (ox-LDL, MDA) were increased and the levels of PON were decreased in ACA-positive CHD.