Abstract: Objective Study on the changes of organism lipid peroxidation level in short term rapid blood loss. Methods The rapid blood loss model of the gradient decerease in the systolic blood pressure was eatablished in 11 new zealand rabbits on ordinary level. The arterial blood during the different phase of shock,i.e.when the systolic pressures were 2/3（T2）,1/2（T3）,1/3（T4）of the basis systolic blood pressure,was collected and malondialdehyde（MDA）、hydrogen peroxide enzyme （CAT）、glutathione oxidation reductase （GSH-P x）levels in the plasma were determined by the double antibody sandwich method of enzyme-labeled immunosorbent assay（ELISH）,and the data be statistically analyzed. Results MDA ：Group B less than in group C,group C less than in group D,there was no significant difference between the time level（P>0.05）. CAT ：Group A higher than in group B,group B higher than in group C,group C higher than in group D,there was no significant difference between the T1-T2,T2-T3,T3-T4（P>0.05）,there were significant differences between the other groups （P<0.05）. GSH-Px ：Group A higher than in group B,group B higher than in group C,group C higher than in group D,there was no significant difference between the T1-T2（P>0.05）,there were significant differences between the other groups （P<0.05）. Conclusion Short term rapid blood loss has a significant effect on the antioxidant enzyme CAT and GSH-Px of organism,can lead to significantly decrease in CAT and GSH-Px activity,MDA levels rise reflect the degree of lipid oxidation. There were significantly correlated between blood loss and CAT,GSH-Px index.

Key words: Lose, blood, Lipid, peroxidation, Malondialdehyde, Antioxidant, enzyme, Hydrogen, peroxide, enzyme, Glutathione, oxidation, reductase, Antioxidant, capacity