Sugar cane bagasse hemicellulose hydrolyzate was prepared by dilute sulfuric acid (3% w/v) hydrolysis with a high-solid, low-liquid ratio followed by leaching. The hydrolyzate contains 11% (w/v) of fermentable sugars with xylose as the major component, which comprises up to 75% of the total reducing sugars. The neutralized hydrolyzate exhibited strong inhibition toward cell growth and ethanol production by yeasts. The inhibitory effect of hydrolyzate can be alleviated by treating hydrolyzate either with ion-exchange resins or with acidified activated charcoal.