Abstract: In order to provide an evidence of brucellosis for diagnosis and prevention, 2D-electrophoresis and SDS-PAGE were applied to detect protein expression difference in plasma between healthy dairy cows and dairy cows suffered from Brucellosis. The results showed that 11 differentially protein spots were found by PDQUest 8.0 Software and 5 of them were detected by ion trap mass spectrum. Apoprotein C-III and Serum Amyloid protein A (SAA) were acute phase protein and lipometabolism-related proteins which can serves as the plasma biomarkers of brucellosis-associated proteins for diagnosis and prevention.