Soybean histones extracted with (>1% glacial acetic acid, 0.4 N HtS04, 0.25 M HCI were separated on 12.5% SDS-poiyacrylamide gel by electrophoresis. The electrophoretic patterns of histones extracted with those various acids were similar, but the quantitative ratio of five classes of histones were difTerent. Histones extracted with 0.25 N HC1 or 0,4 N HtS04 showed betlcr resolution on polyacrylamide gel with less nonhistone basic proteins contaimination than those extracted with glacial acetic acid. Histones extracted with glacial acetic acid showed more bands in slow moving region and these nonhistone basic proteins might be ribosomal proteins. For identification of soybean histones, histones from p«as and calf thymus were used as references. The eleciropboreiic pattern of soybean histones was very similar to that of pea and the electrophoretic mobililies of 113 and H4 from soybean coincided very well wiih those from peas and calf thymus. The order of migration for soybean histones on acetic acid-urca-polyacrylamidc gel was H4>H3>H2b/ll2a>HI.