Abstract: Graphene dispersion in different surfactant aqueous solutions was investigated by absorbance measurements. Polyvinylpyrrolidone (PVP) is an excellent low cost and "green" dispersion agent. By increasing the concentration of the PVP solution, the graphene suspension concentration can reach ~1.3mg/mL, which is higher than those reported previously. This high-concentration graphene dispersion will play an important role in the application of graphene-based materials. A graphene-based membrane was assembled by the evaporation of a PVP-stabilized graphene suspension at the liquid-air interface. The free-standing, self-assembled membrane with a flat surface and ordered structure could find great practical value in a wide range of applications.