Abstract: In order to investigate the application of mass spectrometry (MS) in the renaturation and purification of synthetic peptides,ω-conotoxin MⅦA was chemically synthesized by a solid-phase method.The sample was oxidatively treated in a glutathione-containing buffer,and then purified by ion-exchange chromatography and RP-HPLC.The renaturation and purification efficiencies of synthesized ω-conotoxin MⅦA were subsequently analyzed by MALDI-TOF-MS and tandem electrospray mass spectrometry (ESI-MS/MS).Meanwhile,using an electrophysiological method,its biological activity was also measured.Mass spectrometric and electrophysiological analysis revealed that renatured and purified ω-conotoxin MⅦA possesses the same conformation and physiological activity as those of natural ω-conotoxin MⅦA.