Objective：To discuss the relationship between irisin level in blood and obesity and type 2 diabetes mellitus（T2DM） related parameters. Methods：We recruited 79 T2DM patients and 80 non-diabetic controls. According to body mass index（BMI），these sub－jects were further divided into normal group，obese group，T2DM group，and T2DM obese group. Obesity and T2DM related parameters were measured by automated biochemical analyzer，automated glucose analyzer and automated glyco-hemoglobin analyzer，and the level of irisin and interleukin-1β（IL-1β） was tested by enzyme-linked immunosorbent assay（ELISA）. Analysis of variance（ANOVA） and linear regression analysis were used to analyze the data. Results：The irisin level in T2DM obese group was significantly higher than that in normal group. The irisin level in both obese and T2DM obese group was significantly higher than that in T2DM group. The IL-1β levels in diabetic groups were significantly higher than the level in normal group，and the level of IL-1β in T2DM obese group was significantly higher than that in obese group. Irisin was positively correlated to weight and BMI. The receiver operating character－istic（ROC） curve analysis showed that the area under the curve of irisin in non-diabetic groups and diabetic groups was 0.653 and 0.854 respectively. Conclusion：The irisin level may be related to obesity to a certain extent，but not related to T2DM，which has a certain diagnostic value for obesity in non-diabetic and diabetic populations.