Abstract: 篈 proteome is the entire protein complement expressed by a genome,or by a cell or tissue type. The proteomic research is to identify and characterize the proteins in a cell or tlssue and define their patterns of expression-Matrix-asslsted laser desorption/ionization time of flight mass spectrometry (MALDI/TOF/MS) and electrospray ionization mass spectrometry (ESI/MS) have been proved the powerful techniques for protein and peptide study in the last decade. In this review,the principle of ionization and mass analysis for peptide and protein analysis by MAI,DI/ToF/MS and ESI/MS is described. The current methods employing MALDI/TOF/MS and tandem mass spectrometry for peptide-mass fingerprinting (PMF) and peptide sequencing are also discussed. A highthroughput screening technique based on MALDI/TOF/MS and ESI/MS/MS for Large -scale proteomics is mentioned..