We propose a new method for the hydrothermal decomposition of cellulose using a strong gravitational field to recover useful chemical intermediates. Experiments of decomposition of two kinds of cellulose (microcrystalline and low-crystalline) under a hydrothermal condition were conducted at 250 degrees C for 6 h to a gravitational field of 0.33 x 10(6)G generated by a ultracentrifuge rotating at 80,000 rpm using a specially-designed gravity apparatus. Results, of our strong-gravity hydrothermal treatment of celluloses showed that both celluloses types successfully hydrolyzed to form cello-oligosaccharides and glucose, and surprisingly phenolic compounds such as guaiacol derivertives, which are applicable for the chemicals and food industries. Due to synergism of strong gravitational field with physical properties of water under hydrothermal condition, this unique method is anticipated as a benign technique to covert cellulose to cello-oligosaccharides and glucose via hydrolysis, and valuable phenolic compounds via any rearrangement or unique reactions of cellulose or its hydrolysis products. (C) 2016 Elsevier B.V. All rights reserved.