The synthesis of silver nanoparticles loaded on the activated carbon (AC) surface were performed under SCW condition at 673 K and 31.15 MPa in a batch reactor. In supercritical region, fine particles are rapidly synthesized due to reaction rate increase at low dielectric constant of supercritical water. Samples were prepared with different concentrations of silver acetate solution and various reaction times. The synthesized silver loaded on AC particles were characterized by the Fourier transform infrared spectroscopy (FTIR),X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). FTIR spectrum of primary activated carbon, activated carbon treated under supercritical water condition and synthesized AC-Ag was compared. The particles size and crystallite size of silver deposited on AC surface were analyzed by TEM and XRD, respectively.