MSG was used to estblish the obese rat models. Fifty female modeling rats （whose body mass exceeded 20% of the average body mass of the rats in control group） were randomly divided into model group， metformin group （95 mg·kg^－1）， low dose （15 mg·kg^－1）， medium dose （30 mg·kg^－1） and high dose （60 mg·kg^－1） of genistein chromium groups， another 10 normal rats were used as control group； the test drug was administered by gavage once a day for 4 weeks. After administration， the vein blood was obtained，and the levels of fasting blood glucose （Glu），triglyceride （TG） and total cholesterol （TC） in serum of the rats were measured by oxidase method；the levels of serum glycosylated hemoglobin （GHb） and insulin （INS）， nitric oxide synthase （NOS）， angiotensin Ⅱ （AngⅡ）， endothelin-1（ET-1）， prostacyclin（PGI2）， tumor necrosis factor-α （TNF-α），interleukin-6 （IL-6） were measured by enzyme-linked immunosorbent assay.

Compared with control group， the body masses of rats in the other groups were increased significantly （P<0.05） before and after administration， which proved that metformin group and the models were constructed. After 4 weeks， compared with model group， the body masses of the rats in metformin group and medium and high doses of genistein chromium groups were decreased significantly （P<0.05）；the levels of Glu， GHB and INS in serum of the rats in metformin group and different doses of genistein chromium groups were decreased significantly （P<0.05）； the insulin sensitivity index （ISI） of the rats in metformin group and medium and high doses of genistein chromium groups were increased significantly （P<0.05）； the levels of TG， TC， NOS， AngⅡ， ET-1，TNF-α，IL-6 in serum of the rats in medium and high doses of genistein chromium groups were decreased significantly （P<0.05），and the serum PGI2 levels were increased（P<0.05）； the levels of TC， AngⅡ，TNF-α，IL-6 in serum of the rats in metformin group were decreased significantly （P<0.05）.

Genistein chromium can significantly improve glucose metabolism and lipid metabolism in the MSG-induced obese rats. This effect is related to increasing the insulin sensitivity， improving the endothelial factor and inhibiting the inflammatory factor function.