How to preserve the structure integrity of graphene while enhance its dispersion and compatibility in matrix attracts the attention of researchers in graphene/polymer nanocomposite field. In this paper, methacryloxyethyltrimethyl ammonium chloride (DMC), a kind of ionic liquids, was first used to non-covalently functionalize graphene in the process of graphene oxide (GO) reduction. The as-modified graphene (DMC-rGO) was further incorporated into poly(vinyl alcohol) (PVA) matrix by solution casting technique to fabricate DMC-rGO/PVA composites. The structure and properties of the obtained DMC-rGO were investigated by X-ray diffraction analysis (XRD), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscope (TEM), Atomic force microscopy (AFM), and Raman test. The results showed that graphene could be successfully modified by DMC through ionic- interaction and the structure integrity of the graphene could be reserved by this non-covalently approach. Furthermore, after co-reduction process, some hydroxyl groups were introduced into DMC-rGO. In virtue of these intrinsic properties of DMC-rGO, the fabricated DMC-rGO/PVA composites exhibit considerable enhancements in mechanical properties and remarkable improvements in thermal stability, as well as the enhancement in electrical conductivity at low DMC-rGO loading. This simple modification approach gives a new opportunity to improve the performances of graphene/polymer composites. (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45006.