Objective:To ivestigate the level of atrial natriuretic peptide(ANP) in patients newly diagnosed with type 2 diabetes mellitus(T2DM) and pre-diabetes(pre-DM),and explore its role in the development of T2DM. Methods:A total of 84 subjects enrolled was divided into 3 groups (DM group,pre-DM group and normal group) according to blood glucose. ELISA method was used to detect the serum ANP. Results:The level of ANP in the DM group was lowest,followed by that of pre-DM group,and both of them were lower than the ANP level of control group. There were significant differences among the three groups. Pearson correlation analysis showed that the level of ANP was negatively correlated with FBG and 2hPG(P < 0.01), and was no correlation with TG,LDL-C and HDL-C. Conclusion:The serum ANP is lower with increased blood glucose,and may play a major role in the development of T2DM.