Abstract: The ultrasound-assisted alkaline extraction method was used to investigate the efficient extractability of hemicelluloses from bamboo obtained. The influences of KOH mass concentration, extraction temperature and ultrasonic irradiation time on yield of bamboo hemicelluloses were evaluated under the conditions of constant material/ liquid ratio of 1:20 g/mL and total extraction time of 120 min. On the basis of single factor experiments, the extraction conditions were optimized with Box-Behnken experimental design and response surface analysis. The results showed that the optimal conditions for bamboo hemicelluloses extraction by ultrasound-assisted alkaline extraction method were KOH mass concentration of 3.1%, temperature of 54 ℃, and ultrasonic treatment time of 56 min, under which the actually total yield of hemicelluloses was 19.28%. The extraction temperature and KOH mass concentration were the most significant factors affecting the total hemicelluloses yield, while ultrasonic irradiation time was the least significant factor. Compared with the alkaline extraction without ultrasound assistance, the hemicelluloses yield could be improved by 4.06% using ultrasound-assisted alkaline extraction technology. The results can provide a reference for industrialization of bamboo hemicelluloses production.