Well-dispersed and low Pt content Pt–Ru/C nanoparticles were prepared by a developed impregnating reduction method with sodium citrate as stabilizer. The as-prepared Pt–Ru/C catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and energy dispersive X-ray (EDX) analysis. TEM showed that the Pt–Ru particles were quite uniformly distributed on the surface of the carbon with an average particle size of 3.5–4.5 nm. The effect of pH values on methanol electro-oxidation reaction was examined by cyclic voltammetry (CV) and chronoamperometry (CA). Pre-adsorbed CO monolayer stripping was used to evaluate the antipoisoning ability. The results showed that Pt–Ru/C (pH = 8) catalyst had the highest catalytic activity and stability toward the oxidation of methanol. Finally, comparing Pt–Ru/C (Pt–Ru 20 wt.%, Pt/Ru = 1:1) catalysts with Pt/C (Pt 20 wt.%), the onset potential was 200 mV lower and electrochemical active area was much bigger.