Abstract: Three peraxydases in the erythrocytes of 50 psoriatics were assayed, and the results of the patients were compared with those of the normal control groups. The values showed that the level of GSH-Px, SOD and CAT were significantly lowered than that of the controls stastistically (P value <0.05 or <0.01). Furthermore the lowering of GSH-Px values paralleled with the severity of the disease. These three enzymes might be responsible for the normal metabolism of the organism and play important antagonist roles in the oxydation, and for the protection of biomembranes. Therefore it is worthy to study psoriasis in field of biophysics with the methods of quantum biology.