Abstract: Based on single factor tests,extraction conditions of protein from Phaseolus vulgaris were discussed and the optimum extraction conditions were determined by orthogonal test. The results of orthogonal test showed that the optimum extraction conditions are as follows:temperature 40 ℃,extraction time 60 minutes and proportion of materials to 0.067 mol/L PBS at pH 10.0 1:20. The application of ultra filtration technology in purification of protein was also discussed. On the conditions of pressure 0.3 MPa,pump power 20% and solution at pH 10.0,concentration 4% after four times ultra filtration,the protein purity is up to 85%.

Key words: Phaseolus vulgaris, protein, extraction, separation by ultra filtration technology