Abstract: This paper deals with the determination of lipoperoxides (LPO) in plasma, superokide dismustase(SOD),Glutathion peroxidase (GSH-PX) and Glutathion (GSH) in blood in 29 cases withmalignant osteoma, 38 cases with benign osteoma and 21 cases with non-tumorous disease of bone,The results showed that both SOD and GSH differed significantly (P0.01 for SOD and P0.05for GSH) in malignant osteoma, benign osteoma and nontumorous disease of bone,while conentof plasma LPO tended to increase in all three groups with no significant difference (P0. 05). Astepwise discriminant analysis of these four indices in the three groups indicated a sensitivity of94.03% and a specificity of 38. 1% in combined LPO and SOD. This can be used as clinical accessory diagnosis.