Abstract: Objective: To analyze the peptide mass mapping of recombinant human endostatin (rhEndostatin) by HPLC-ESI-Q-TOF MS. Methods: rhEndostatin was digested by trypsin at 37 ℃ over night, and the peptides was separated by HPLC, and the molecular weight of the peptides was measured by ESI-Q-TOF MS. Results: The peptides from rhEndostatin were assigned by analyzing the retention time and molecular weight. The theoretical peptides of 68％ were detected. Conclusion: The study proves that HPLC-ESI-Q-TOF MS is a good method to analyze peptide mass mapping of protein with advantage of high sensitivity, speed and accuracy.