Classical molecular dynamics is used to investigate the equilibrium state of the surface region and interface of heteroepitaxial La 2 O 3 thin films. Due to the lattice mismatch, heteroepitaxial thin films are subject to very large stress. For this reason the behavior of La 2 O 3 thin films at SiO 2 interface becomes an important concern. Our result indicates that La 2 O 3 can uniformly wet SiO 2 surface. The properties of the simulated films are analyzed and the lack of any discernible crystalline phase in epitaxial La 2 O 3 on SiO 2 indicates that the lattice mismatch between SiO 2 and La 2 O 3 is sufficiently large to prevent the formation of even short-range orders in La 2 O 3 film.