Graphene, a new carbonous material with two-dimensional (2D) nanostructure, has attracted great attention both in fundamental science and applied research. Polymer nanocomposites have been the subject of fundamental scientific interest due to their immense applicational potential and could be used in differential application. Among the conducting polymers, polyaniline (PANI) is the most promising material for electronic application due to its excellent capacity for energy storage, easy synthesis, high conductivity, and low cost. Graphene were applied in PANI to produce graphene filled PANI nanocomposite. In this study, PANI was synthesized by using interfacial polymerization. Graphene filled polyaniline nanocomposites were fabricated by sonochemical method. The morphology and properties of the composites were characterized by scanning electron microscopy (SEM), high resolution transition electron microscopy (HRTEM), fourier transform infrared (FTIR) spectroscopy and electrical conductivity test. Graphene filled PANI nanocomposites has great applicability in electronic, optical and magnetic materials. From the results of four point probe resistivity measurement, graphene filled PANI nanocomposite shows better electrical conductivity, 17.2831 S/cm which increases around 17 times compared to pure PANI, 1.1617 S/cm.