Mesoporous aligned hematite nanoflakes (MA-alpha-Fe2O3) were in situ electrochemically synthesized on the fluorine-doped fin oxide coated glass (FTO) substrate and studied for electrocatalytic reduction and sensing H2O2. Morphology and crystallinity of films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM). The vertical aligned MA-alpha-Fe2O3 mesostructured films showed (1 1 0) preferential growth, offering both the fast electron transfer path and diffusion of reactants and products. Thus the sensing performance of MA-alpha-Fe(2)O(3 )displayed an unprecedented sensitivity of 422.5 mu A/(mM cm(2)), a wide linear range up to 3.145 mM and an excellent detection limit of 22 mu M. Furthermore, the sensor also exhibited good anti-interference, reproducibility, stability, feasibility for real sample detection. These results indicated that MA-alpha-Fe2O3 could be a promising electrochemical material as nonenzymatic H2O2 sensor.