Graphite nanosheets (GNS) were fabricated in water through assistance of high pressure homogenization (HPH). Poly (vinyl alcohol)/graphite nanosheets (PVA/GNS)composites were prepared by varying the amount of GNS loading in the solution. The morphology of the GNS was characterized by the SEM and AFM. It is found that HPH can exfoliate graphite efficiently and the prepared GNS has better stability in PVA solution than graphite. The percolation threshold of PVA/GNS composite at room temperature is as low as 3.36%(volume fraction), much lower than that of the composites filled with conventional graphite particles. The conducting behavior of the composites is interpreted by percolation theory.