Aim To investigate the influence of Ramu-lus mori polysaccharides ( RMP) on blood glucose and anti-oxidative effect in streptozotocin ( STZ )-induced diabetic mice .Methods Diabetic mice were induced by intraperitoneal injection with 120 mg? kg -1 STZ and were randomly divided into the following 5 groups with 20 animals per group: model group , valsartan group ( 20 mg? kg -1 ) , low-, medium-, high-dose (0.3,0.6,1.2 g? kg -1 ) of RMP groups.Other 20 normal mice were treated as normal control group .The mice were administered orally for 90 d.On 45 d of ad-ministration , the 24 h urine was collected through met-abolic cages for urine protein detection .Pathological changes of kidney tissues were observed through HE staining .The serum levels of urea nitrogen ( BUN) and creatinine ( Cr ) were detected by automatic biochemical analyzer; and the manganese superoxide dismutase (Mn-SOD), catalase(CAT), malonaldehyde(MDA) and mitochondrial respiratory chain complex Ⅰ,Ⅲac-tivity of kidney tissues were also determined .ELISA method was used to detect ROS content in renal cortex . The SIRT1 , FOXO1 and NF-κB protein expressions were analyzed by Western blot .Results Compared with model group, the FBG, microalbuminuria, BUN and Cr were decreased by RMP medication ( P <0.05).The activities of Mn-SOD, CAT and mitochon-drial respiratory chain complex Ⅰ,Ⅲ in RMP groups were enhanced , while MDA and ROS levels were re-duced. Moreover, the expressions of SIRT1 and FOXO1 were up-regulated by RMP , the expression of NF-κB was down-regulated ( P<0.05) .Conclusion RMP exerts renal protective effect through up-regula-ting the expressions of SIRT1 and FOXO1 in renal cor-tex , which may relate to the improvement of anti-oxida-tive capability .