Abstract: A proteomic approach to cisplatin resistance and drug response in human ovarian adenocarcinoma cell line, COC1.The global proteins have been separated by 2DE SDSPAGE. The image analysis revealed obvious differential protein expression of the cells in response to cisplatin treatment. Primary result shows there were 3 protein spots with magnificent differential expression. The proteins, including two upregulated protein spots and one down-regulated protein spots, were analyzed by matrix assisted laser desorption/ ionization timeofflight mass spectrometry (MALDI-TOF-MS) and database search. Some of them were the first time detected to be relevant to the drug resistance.