The development of non-precious metal catalysts with excellent water oxidation catalytic properties is important for both energy storage and water spilting.Free from any template and surfactant,three dimensional nano-flowered iron-nickel bimetallic complexes composed of twodimensional nanosheets have been formed by use of the strong coordination ability of tartaric acid through one-step solvothermal self-assemble method.It shows excellent catalytic activity and cycle stability.The overpotentials of current density of 100 mA/cm2 and 250 mA/cm2 are 237 mv and 329 mv,respectively.Moreover,tafel plot is 38.7 mV/dec.Furthermore,mild increases in overpotential are observed even after continuous 120 h i-t test and 10000 th voltammetric cycle under alkaline conditions.XPS and UV diffuse reflection prove that the iron-nickel bimetallic complex with the tartaric acid can form a large π bond after the catalytic reaction,which lead to excellent catalytic activity and stability.The DFT calculation further confirms that the four-steps elementary reaction of FeNi metal organic framework compound(FeNi-MOF)catalyzed oxygen evolution is an exothermic reaction and is thermodynamically feasible.The in-situ Raman detection of the catalyst confirm that FeOOH and NiOOH formed during the catalytic process,which is the catalytic active site.