The water dispersion of reduced graphene oxide (rGO) was prepared by reducing the graphene oxide (GO) with sodium borohydride, and three-dimensional ordered polyaniline-graphene nanocomposite with high-surface-area was successfully fabricated via in situ chemical oxidative polymerization. The surface morphology and structure were investigated by using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectrometer (XPS) and X-ray diffraction (XRD). The results exhibited that the surface area of the nanocomposite was as high as 131 m2/g which was higher than that of pure PANI (32.71 m2/g), and polyaniline (PANI) nanorods with diameter of 10~20 nm were uniformly aligned on surfaces of rGO nanosheet. The composite had a high specific capacitance of 358 F/g at a charge-discharge current density of 0.5 A/g, which was higher than that of rGO and pure PANI. The capacitance retention ratio of the composite reached 74.3% when the current density increased from 0.5 to 10 A/g, indicating enhanced rate performance. Furthermore, the composite showed 83.7% capacitance retention after 500 cycles charge-discharge at high current density of 10 A/g.