Herein, (3-aminopropyl)triethoxysilane functionalized cerium (IV) oxide (CeO2-NH2) supported Pd nano particles were synthesized. The nanocomposites were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and High-resolution transmission electron microscopy (HRTEM). The Pd@CeO2-NH2 showed better electrocatalytic response to the reduction of H2O2 than CeO2-NH2. The fabricated sensor exhibited two linear responses to the reduction of H2O2. The first one was from 0.001 to 3.276 mM with 0.47 mu M of a limit of detection (LOD) (S/N = 3) and excellent sensitivity of 440.72 mu A mM(-1) cm(-2) and the second one was from 3.276 to 17.500 mM with the sensitivity of 852.65 mu A mM(-1) cm(-2) in the optimum conductions. Also, the sensor exhibited 91% of electrocatalytic activity toward H2O2 after having been used for 30 days and the reproducibility was also satisfactory. The sensor response to H2O2 was not affected by ascorbic acid, fructose, glycine, dopamine, arginine, mannose, glucose, uric acid, Mg+2, Ca+2, and phenylalanine at the studied potential. Also, the fabricated sensor was used to determine H2O2 in milk samples. The results show that the constructed sensor can be a promising devise for the determination of H2O2 in real samples.