Objective:To explore the protective mechanism of Xinjia Xiayuxue Tang on kidneys in diabetic rats by investigating the effect of Xinjia Xiayuxue Tang on bone morphogenetic protein 7（BMP7） and transforming growth factor β1（TGFβ1）in kidneys of diabetic rats.Method:SD rats were divided into control group and diabetes model group.The diabetes model was established by injection of alloxan through vena caudalis

and then were randomly divided into diabetes model（DM） group and Xinjia Xiayuxue Tang-treated group.After 12 weeks

The fast-ing blood glucose（FBG）

serum creatinine（Scr）

urine protein（Upro） were checked with biochemical methods.The morphological changes of renal tissue were examined under microscopy on sections stained with PAS.The mRNA expression of BMP7

TGFβ1 and plasminogen activator inhibitor 1（PAI1）were tested by RT-PCR.Result:Compared with DM model group

in Xinjia Xiayuxue Tang-treated group

FBG

Scr and Upro were markedly decreased（P < 0.01）;renal damage were significantly reduced

the expression of TGFβ1 and PAI1 mRNA were significantly reduced

BMP7 mRNA expression was greatly increased.Conclusion:Xinjia Xiayuxue Tang exerted protective effect on diabet-ic nephropathy probably via elevation of BMP7 and reduction of TGFβ1

then reducing the expression of PAI1.