The extraction of hemicellulose using pressurized hot water is an environmental-friendly process for the extraction of hemicelluloses from lignocellulosic biomass. However, this process requires high temperature, in the range of 180°C to 210°C, for the extraction of hemicelluloses. This energy-demanding condition leads to undesired sugar degradation which results in the formation of impurities such as acetic acid, HMF and levulinic acid due to degradation of acetyl moieties and side chain from hemicelluloses and consequently less branched hemicelluloses with varying lignin content are obtained. Hemicelluloses were isolated from sugarcane bagasse under mild reaction condition (140°C and 150°C) using inexpensive sea water as solvent. The more branched arabino-xylan hemicelluloses with lesser lignin content were obtained and were characterized by FT-IR, 1H-NMR, 13C NMR SEC-MALLS and pyrolysis GC-MS techniques.