Rational synthesis of a new class of electrocatalysts with high-performance and low-cost is of great significance for future fuel cell devices. Herein, we demonstrate a general one-step simultaneous reduction method to prepare carbon-supported Pd M(M = Co, Fe, Ni) alloyed nanodendrites with the assistance of oleylamine and octadecylene. The morphology, structure and composition of the obtained Pd M nanodendrites/C catalysts have been fully characterized. The combination of the dendritic structural feature and alloyed synergy offer higher atomic utilization efficiency, excellent catalytic activity and enhanced stability for the formic acid oxidation reaction(FAOR). Strikingly, the as-synthesized Pd Co nanodendrites/C catalyst could afford a mass current density of 2467.7 A g~(-1), which is almost 3.53 and 10.4 times higher than those of lab-made Pd/C sample(698.3 A g~(-1)) and commercial Pd/C catalyst(237.6 A g~(-1)), respectively. Furthermore, the PdC o nanodendrites/C catalyst also exhibit superior stability relative to the Pd/C catalysts, make it a promising anodic electrocatalyst in practical fuel cells in the future. Additionally, the present feasible synthetic approach is anticipated to provide a versatile strategy toward the preparation of other metal alloy nanodendrites/carbon nanohybrids. Rational synthesis of a new class of electrocatalysts with high-performance and low-cost is of great significance for future fuel cell devices. Herein, we demonstrate a general one-step simultaneous reduction method to prepare carbon-supported Pd M (M = Co, Fe, Ni) alloyed nanodendrites with the assistance of oleylamine and octadecylene. The morphology, structure and composition of the obtained Pd M nanodendrites / C catalysts have been fully characterized. The combination of the dendritic structural feature and alloyed synergy offer higher atomic utilization efficiency, excellent catalytic activity and enhanced stability for the formic acid oxidation reaction (FAOR). Strikingly, the as-synthesized Pd Co nanodendrites / C catalyst could afford a mass current density of 2467.7 A g -1, which is almost 3.53 and 10.4 times higher than those of the lab-made Pd / C sample (698.3 A g -1) and commercial Pd / C catalyst (237.6 A g -1) respectively, the PdC o nanodendrites / C catalyst also ex hibit superior stability relative to the Pd / C catalysts, make it a promising anodic electrocatalyst in practical fuel cells in the future. .