Abstract: In this work, PdxCoy/rGO nanocomposite catalysts with different Pd:Co ratios were prepared by electrodeposition. The structure and morphology of the prepared catalysts were characterized by Field emission scanning electron microscope, X-ray energy dispersive spectroscopy and Fourier transform infrared. The results indicate that the compositions of the as-synthesized electrocatalysts are close to the metal ion concentration ratios in the precursors. The metal particle sizes of the PdxCoy/rGO binary electrocatalys are smaller than the particle sizes of Pd/rGO and Co/rGO monometallic electrocatalysts. The size distributions of the PdxCoy/rGO binary electrocatalys are more even in comparison with those of the Pd/rGO and Co/rGO monometallic electrocatalysts. The Pd1Co3/rGO nanocomposite catalyst exhibits the largest electrochemical active surface area in 0.5 M H2SO4 electrolyte, and demonstrates the highest electrocatalytic activity and the best stability for formic acid electrooxidation. The results indicates that the as prepared Pd1Co3/rGO nanocomposite catalyst by electrodeposition is very promising for application in direct formic acid fuel cell.