[Abstract]  Objective  To explore the influence of specimen collection tube and preservative way on the determination results of superoxide dismutase(SOD). Methods      80 subjects are randomly selected from The Second Affiliated Hospital, Hubei University of Science and Technology. Firstly, 40 subjects blood specimens were simultaneously put  in separation gel coagulant vacuum tubes (marked as A group) and  in no anticoagulation vacuum tubes(marked as B group). Secondly, 40 subjects blood specimens were  put  in separation gel coagulant vacuum tubes (marked as C group) .After centrifugal separation , A group serum be preserved at room temperature, then detect the SOD respectively after 0h, 4h, 6h, 8h and 10h. B group serum be preserved at room temperature, then detect the SOD  after 0h.C  group serum  will be preserved at 2-8℃ refrigerator, then detect the SOD respectively after 0h,10h,14h and 21h. Results The differences of the determination of SOD between separation gel and no anticoagulation vacuum tubes are not statistically significant (P>0.05). But the determination results of SOD, which are detected in separation gel coagulant vacuum tubes after 4h, 6h, 8h, 10h at room temperature, are statistically significantly different from the ones detected at 0h(P<0.01),and the relative bias of 4h, 6h, 8h, 10h are 3.719%，5.341%，6.807%，8.306% respectively in comparison with 0h. So are specimens in no anticoagulation vacuum tubes and preserved at 2-8℃ refrigerator, the relative bias of 10h, 14h, 21h are 3.213%，4.552%，5.816% respectively in comparison with 0h. Conclusions  Firstly, it is reasonable to use separation gel coagulant vacuum tubes for the specimen collection. Secondly, the determination results of specimens in separation gel coagulant vacuum tubes, both the ones after 10h at room temperature and the ones after 21h at 2-8℃ refrigerator are in the clinical acceptable range. The preservative time can be prolonged by more than 1 times compared with the required time in the product specification.