The structural stability of beta-Ti3O5 (C2/m) has been investigated by X-ray diffraction and Raman spectroscopy with diamond anvil cells. beta-Ti3O5 is stable up to about 26 GPa at room temperature. Isothermal pressure-volume relationship of beta-Ti3O5 is well presented by the third-order Birch-Murnaghan equation of state with V-0=348.6(8) angstrom(3) and B-0=216(9) GPa. Axial compressibility presents obvious anisotropy. The a-axis and c-axis are more compressible than b-axis due to the different crystal structure arrangement of beta-Ti3O5 along b-axis and perpendicular to b-axis direction. The Gruneisen parameters of thirteen observed Raman modes are 0.79-1.74, whose mean is 1.32. Crown Copyright (C) 2012 Published by Elsevier Inc. All rights reserved.