n this paper, a non-enzymatic hydrogen peroxide (H2O2) sensor, based on Au nanoparticles (AuNPs) electrodepos‐ ited on an electrochemically reduced graphene oxide(ER‐ GO)-Nafion modified glass carbon electrode (GCE), was reported. The graphene oxide-(GO-)Nafion nanocompo‐ sites were first assembled on the GCE surface to produce a GO-Nafion electrode. GO was then electrochemically reduced to produce an ERGO-Nafion modified GCE (to be subsequently denoted as GCE/ERGO-Nafion). Afterwards, AuNPs were electrodeposited on the modified GCE to form a GCE/ERGO-Nafion/AuNPs electrode. The ERGO-Nafion nanocomposites and the electrodeposited AuNPs were characterized by infrared spectroscopy and scanning electron microscopy (SEM). The results showed that the GO was reduced successfully and the AuNPs were uniformly dispersed on the GCE/ERGO-Nafion electrode with a size of about 48nm. The cyclic voltammograms and the am‐ perometric method were used to evaluate the electrocata‐ lytic properties of the GCE/ERGO-Nafion/AuNPs electrode. The results showed that the modified electrode displayed good electrocatalytic activity in relation to the reduction of H2O2 with a detection limit of 2 μM of (H2O2) based on a signal-to-noise ratio of three. The sensor also indicated great sensitivity (574.8 μA/(mM cm2)), wide linear range (0.02-23 mM), good selectivity and reproduci‐ bility, and long-term stability.