Adipsin, as an adipokine, has an important role in maintaining beta cell function. However, the association between adipsin and clinical parameters in type 2 diabetic(T2DM) patients remains unclear. We investigated plasma adipsin concentrations in three distinct patient groups: normoglycemia, T2DM, and T2DM with possible beta cell failure treated with insulin. Plasma adipsin concentrations were significantly decreased in T2DM treated with insulin, compared to T2DM without insulin treatment. Furthermore, adipsin had significantly positive correlations with fasting serum C-peptide concentration, 2h C-peptide, and 2h C-peptidogenic index. Interestingly, the normoglycemic and T2DM groups did not exhibit a significant correlation between adipsin and other clinical parameters. Also, we found significant T2DM-associated variants within adipsin, Using the TIGER portal. Our findings suggest that adipsin may be a potential biomarker of pancreatic beta-cell function in T2DM with possible beta cell failure.