By the use of solvent partition, ion-exchange column chromatography, and the soybean callus bioassay, cytokinin-like substances were detected in extracts of etiolated whole leaves and leaf segments of barley, Hordeum vulgare L. cv. Pallas. The active material was retained by a cellulose phosphate column at pH 3�1 (cation exchanger) but not by a DEAE-cellulose column at about pH 6 (anion exchanger). This is consistent with the view that the active substance(s) is an N6-substituted purine derivative in the free base or nucleoside form. Preliminary attempts at characterization of the cytokinin(s) are reported.