We investigated the structure and thermodynmnic properties of the hexagonal Ce2O3 by using LDA+U scheme in the fi'ame of density functional theory (DFT), together with the quasi-harmonic Debye model. The obtained lattice constants, bulk modulus, and the insulating gap agree well with the available experimental data. We successfully yielded the temperature dependence of bulk modulus, volume, thermal expansion coefficient, Debye temperature, specific heat as well as the entropy at different U values. It is found that the introduction of the U value cannot only correct the calculation of the structure but also improve the accurate description of the thermodynamic properties of Ce2Oa. When U = 6 eV the calculated volume (538 Bohra) at 300 K agrees well with the experimental value (536 Bohr3). The calculated entropy curve becomes more and more close to the experimental curve, with the increasing U value.