Abstract: Uniform Ag/Pd alloy nanoparticles absorbed on the surface of cellulose nanocrystal(CNC)were prepared by chemical reduction of metallic cations using NaBH4. CNC played a role of a dispersant to obtain stable dispersions of alloy nanoparticles. Aqueous suspensions of Ag/Pd alloy nanoparticles was detected by UV-vis spectroscopy and transmission electron microscopy(TEM), and the dried nanocomposites was characterized by X-ray diffraction(XRD). The average sizes of alloy nanoparticles were below 5.5 nm and their average diameter was increased with an increase of Pd content.