Abstract: AimTo analyze the peptide mapping of recombinant human interleukin-11 (rhIL-11) by HPLC-ESI-Q-TOF/MS spectrometry. MethodsThe trypsin digested rhIL-11 at 37 ℃ over night, and the peptide mapping was performed by HPLC. The relative molecular weight of the peptides fragments was measured by ESI-Q-TOF/MS, and amino acid sequence was analyzed by MS/MS. ResultsThe peptide fragments of rhIL-11 in the peptide mapping were assigned by analyzing the retain time, relative molecular weight and amino acid sequence. And 97% of the expected peptides were detected in this way. ConclusionThe study proves that HPLC-ESI-Q-TOF/MS is a good method to analyze peptide mapping of protein with the advantage of sensitivity, high speed and accuracy.