The interface between graphene and substrate plays a very important role in graphene-based advanced devices. We examine the thermal boundary resistance R of the graphene/silicon dioxide (Gr/SiO2) interface by using molecular dynamics simulations. R decreases monotonically with the increase of temperature and exhibits a strong dependence on the substrate coupling strength. Due to the polycrystalline nature of graphene, we show that the presence of periodic 5-7, 5-8-5 and 5-7-5-7 grain boundaries in graphene enhances phonon transmission across the Gr/SiO2 interface, which are attributed to both the increased overlap in the phonon spectra and more inelastic scattering at the interface. (C) 2017 Elsevier B.V. All rights reserved.