Silicene, a two-dimensional hexagonal lattice of silicon, has been synthesized recently and exhibits fascinating electronic properties that resemble graphene.The substrate effect on the electronic properties of silicene is important for the practical applications of silicene.First-principles calculations were performed for silicene on two kinds of representative inert substrates, i.e., hexagonal boron nitride (h-BN) monolayer and SiC(0001) surface.