The phenolic compounds contained in milled barley grains were seperated and identified by gas liquid chromatography and the effects of phenolic compounds extracted from milled barley grains and each authentic phenolic compound on the growth of Saccharomyces cerevisiae were studied. Severn phenolic acids, namely cinnamic, protocatechuic, ferulic, sinapid, vanillic, syringic, gallic acids, were identified in milled barley grains by gas liquid chromatography. The contents of sinapic, ferulic, cinnamic, protocatechuic acids were larger than those of vanillic and gallic acids. Phenolic compounds, extracted from milled barley grains and supplemented in culture broth, were inhibitory to the growth of Saccharomyces cerevisiae at levels above 100ppm to 24 hours but not inhibitory at all levels after 48 hours. Cinnamic, ferulic, vanillic acids at all levels were inhibitory to the growth of Saccharomyces cerevisiae, among them cinnamic acid was most inhibitory. Syringic acid was inhibitory to the growth of the yeast at the initial stage of culture. But sinapic and protocatechuic acids were slightly stimulatory to the growth of the yeast and gallic acid was ineffective to the growth of the yeast.