An enzyme-free electrochemical sensor for the detection of hydrogen peroxide was developed using a nano-composite（Ce1-xGdxO（4-x）/2） modified electrode.The nano-composites were synthesized by hydrothermal method and characeterized by X-ray photoelectron spectroscopy（XPS），scanning electron microscope（SEM），transmission electron microscope（TEM） and X-ray diffractometer（XRD）.The nanocomposites show the typical CeO2 cubic fluorite structure，and the diameter of the composite is about 20 nm.A novel nanoscale hybrid materials nonenzymatic sensor was constructed by immobilizing Ce1-xGdxO（4-x）/2 and chitosan onto glassy carbon electrode（GCE）.The modified electrode was investigated by cyclic voltammetry（CV） and chronoamperometry（I-t）.Under the optimized conditions，the sensor showed a wide dynamic range for the detection of hydrogen peroxide，which catalytic current was linear with hydrogen peroxide concentration in the range of 1.0×10-5-1.1×10-2 mol/L with a detection limit（S/N=3） of 1.7×10-6 mol/L.The sensor is not good enough in sensitivity，but it might have potential applications in the fabrication of nonenzymatic sensor.