In this work, Au nanoparticles - polyaniline (AuNPs-PANI) binary nanocomposite was prepared with a facile onepot method. The nanocomposite was obtained with simultaneous oxidation of aniline monomer by HAuCl4, reduction of metal salt and formation of Au nanoparticles inside the polymeric structure in dodecyl benzene sulfonic acid (DBSA) medium. The nanocomposite samples were characterized with Fourier transform infrared spectrophotometer (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), UV-vis spectra, field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscope (TEM). The electrochemical performance of AuNPs-PANI electrodes was investigated with cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) in 1 M H2SO4 electrolyte. The nanocomposite containing Au nanoparticles with 40-60 nm sizes embedded in PANI structure was successfully obtained. The prepared AuNPs-PANI (AuNPs-PANI8; aniline/HAuCl4 molar ratio 8:1) exhibited high electrochemical performance with specific capacitance of 292.2 F/g at 0.5 A/g current density.