Abstract: In this paper, a protein determination ethod which involves the binding of coomassie brillant blue G-250 to protein is described. It can be ust to determine micro-gram protein with microscanner and 96-well plates, The advantages of the method include: good reproduction （c.v=5%, n= 15）, a little sample （20）, simplicity and rapidity in processing （88 samples per hour）. This method may increase the efficiency of work evidently, when a large amount of protein samples are determinated. This method can be used not only to determine the quantity of protein during the processes of laboratory separation and extraction, but also to determinate the proteins of almost all body fluids in the clinical diagnosis.