Abstract: Serum amyloid A (SAA) is one of the four inflammation biomarkers in clinical diagnosis. At present, there is no SAA certified reference materials, which cannot achieve traceability and standardization in clinical SAA diagnosis. In this study, the recombinant human serum amyloid A expressed in E. coli was selected as the raw material, and it was qualitatively and quantitatively analysed to study the traceability method. The purity and molecular weight of SAA were analysed by gel electrophoresis, liquid chromatography and mass spectrometry. The results showed that the purity of SAA was >98%, and the molecular weight of 11820.09 Da was consistent with the theoretical value. An absolute quantification method of amino acid analysis-isotope dilution mass spectrometry for SAA was established. The content of phenylalanine, isoleucine and proline in the hydrolysed sample was determined at 8 h of hydrolysis, and the mass concentration of SAA solution was 9.32 µg/g (RSD = 0.91%). An absolute quantification method of signature peptide-isotope dilution mass spectrometry for SAA was established. Within the mass ratio of trypsin and SAA was 1:1 and digestion time was 8 h, the content of peptide EANYIGSDK, GPGGVWAAEAISDAR was detected by IDMS, and the mass concentration of SAA is calculated to 9.41 g/g (RSD = 0.49%). The results of the two methods were consistent by statistical test, and there was no significant difference shown. The quantitative results of this study are traceable to SI units, which lays a foundation for the development of SAA reference materials.