OBJECTIVE： To observe the effect of metformin on related indicators of obese patients with type 2 diabetes. METHODS： 136 obese patients with type 2 diabetes were randomly divided into control group and observation group. All patients were given conventional examination， conventional education about diabetes， diet control and stressed physical exercise. Based on it， control group was given 80 mg Metformin tablet（Ⅱ），once a day， and monitored blood glucose levels， the dosage was adjusted based on fasting blood glucose levels to ensure blood glucose in 3.9-6.1 mmol/L； observation group was given 0.5 g Metformin enteric-coated tablet， twice a day. The 2 groups were compared after 12 weeks treatment. The glycated hemoglobin （HbA1c）， body mass index （BMI）， resistin， insulin-like growth factor-1（IGF-1）， inflammatory cytokines [interleukin-1β（IL-1β）， interleukin-6 （IL-6）， tumor necrosis factor-α （TNF-α）， high-sensitivity C-reactive protein （hs-CRP）] levels in 2 groups before and after tveatment were observed，and the incidence of adverse reactions in 2 groups was recorded. RESULTS： After treatment， resistin，IGF-1， IL-6 and hs-CRP levels in 2 groups were significantly lower than before， and observation group was lower than control group； the differences were statistically significant（P＜0.05）；BMI，IL-1β and TNF-α levels in obser vation group were significantly higher than before and control group， the differences were statistically significant（P＜0.05）； HbA1c level in 2 groups was significiantly lower than before，the difference was statistically significant（P＜0.05），but there was no significant difference between 2 groups（P＞0.05）； BMI level in observation group was lower than before and control group， and there was no significant difference in the incidence of adverse reactions between 2 groups（P＞0.05）. CONCLUSIONS： Metformin can effectively improve insulin resistance in obese patients with type 2 diabetes and inhibit the inflammatory reaction.