The aim of this paper was to investigate the hypoglycemic effects and mechanism of the kelp in diabetic model rats induced by alloxan.Sixty healthy male rata were used to establish diabetes memms(DM)models by injecting alloxan petiteneally,and the kelp powder was applied as additive in general forage to treat the rata.The levels of fasting blood glucose(FBG)were detected bY automatic blood glucose device.Enzyme linked immunoabsorbant assay was appHed to determine the insulin leveh in serum.The serum levels of malondialdehyde(MDA)were measured by thiobarbnuric acid assay and nitric oxide(NO)by nitrate reductase assay.The activities of superoxide dismutase(SOD) were determined by xanthinoxidase assay and glutathione peroxidase(GSH-Px)by chemical eolometry.The shape and structure of islet cells were observed with histopathologieal staining,and the expression of superoxide dismutase(SOD) and laduclble nitric oxide synthase (NOS)in islet cells were detected by immunohistoehemical may.The results showed that the serum levels of insulin after treated with kelp powder inceased significantly than that in DM-model greup，wlille the FBG in the middle-high dose treated groups decreased significantly than those in DM-medel group (P<0.05).The leveh of MDA and NO In kelp powder groups were lower than those in DM-medel group,while the activities of SOD ud GSH-Px were higher than those in DM-model group,of which the significant difference existed between the middle-high dose treated groups and DM-modei group(P<0.05)The shape and structure of islet cells impmved with the up-expressing SOD and down-expressing iNOS in middle-high dose treated groups than those in DM-modelgroup(P<0.05).There were no significant differences between the middle and high dose treated groups all above indexes(P>0.05).It is suggested that kelp might recover the islet cell secreting function and reduce the level of FBG by antioxidant effect.