Proteomics research includes identification and quantitation of single protein and/or protein complex, profiling of protein expression changes in response to biological perturbations, characterization of protein functions and interactions, and elucidation the linkage between proteins and diseases. In this review paper, recent developments in the basic technologies involved in the proteomics research such as 2-dimensional PAGE and mass spectrometry are discussed. Also, the application areas of proteomics technology such as protein expression mapping and cell map proteomics are introduced with the focus on new drug development.