The production of bassinosteroid-like substances of two hybrid types of Korean rice, Jangseongbyeo, Taebackbyeo were investigated. The shoots at the maximum tillering stage were extracted and purified by solvent fractionation, silica gel adsorption chromatography Sephadex LH-20 chromatography, charcoal adsorption chromatography, Bondesil chromatography and HPLC of reverse phase, successively. Biological activities of each purification step were monitored by the rice lamina inclination test. Higher activities against the rice lamina inclination test in the each purification step showed that the shoots of two cultivars biosynthesize brassinosteroids. Two cultivars also showed a similar distribution of biological activities of endogenous brassinosteroids detected by HPLC.