Abstract:Hypocotylar explants of Onobrychis viciaefolia Scop. were cultured on LS basal medium supplemented with 1 mg/l BA and 1 mg/l KT. After two weeks of culture, calli were initiated on the surface of sections. Light-Yellow callus from .one of the explants was selected and proliferated on the medium above. Then it was transfered to LS medium with 1 mg/l BA to initiate somatic embryogenesis. The activity of RNA synthesis increased rapidly during the first two days. Of embryogenic culture and then decreased, but on the 5th day increased gradually. The activity of protein synthesis increased during the first three days and was the highest on the 3rd day. The activity of DNA synthesis had no mark change and emerged, a small peak on the 5th day. All the activities of syntheses of DNA, RNA and protein were higher on embryogenic culture than on nonembryogenic culture.