||Polymers considerably play a role in pharmaceuticals, flexible electronics, and food packaging industries due to functionality, ease of processing, and lightweight. Despite containing these versatilities, limiting property of polymeric materials in food packaging is their inherent permeability such as gases and vapors. The barrier properties of polymers can be significantly enhanced by including impermeable two-dimensional structure such as graphene, with high aspect ratio to change the diffusion path of gas-penetrant molecules. To use with filler and polymer, however, it is important to proper modification between graphene and polymer to improve compatibility. In this study, we fabricated the alkylated graphene oxide/poly(vinylidene chloride) nanocomposite films by modifying the surface of fillers, and confirmed the reduction of the water vapor transmission rate (~0.2 g/m2 day) compared with the neat film (~1.8 g/m2 day).