The powder of Ce0.8Sm0.2 O2-δ(SDC) and Sm0.5Sr0.5CoO 3-δ（SSC）was synthesized by the sol-gel method,The products were characterized by XRD、TEM and SEM measurements. Ammonia was synthesized from wet hydrogen and nitrogen at atmospheric pressure in the solid state proton conducting cell reactor with added voltage, using Sm0.5Sr0.5CoO 3-δ（SSC） and Ni-Ce0.8Sm0.2O 2-δ（SDC） as cathode, sulfonated Poly Sulfone Proton Exchange Membrane as electrolyte, Ni/Ce0.8Sm0.2O 2-δ(SDC) as anode, and silver-platinum as current collector . Protonic conductivity was tested at low temperature from 25℃ to 120℃. The result demonstrated that ammonia is synthesized in this range of temperature,by using SDC and SSC as cathode ,and SSC has the higher rate of evolution of ammonia,the highest rate is up to 6.5×10-9 mol/cm2.s at 80 ℃.