Abstract: An in vitro aging model was set up by methylglyoxal and human serum albumin based on maillard reaction according to cross-linking theory to evaluate aging degree individually. HPLC-ESI TOF MS and ¹⁸O-labeling technique were employed to quantify modification degree of peptides cleaved from HSA, which can indicate aging degree. The in vitro aging model was set up successfully, and all experimental conditions were optimized. This method was considered to be a good foundation for screening aging biomarkers in the future by quality evaluation of the optimized conditions.