A series of Fe45.51(Al2O3)54.49 nano-granular films were prepared using ion-beam sputtering technique. A saturated hall resistivity of about 12.5μΩ.cm at room temperature was observed. The transmission electron microscopy image showed that very small Fe particles of smaller than 1 nm are embedded in Al2Os matrix, and connected into network. The measured ρ- T curve indicated that this giant Hall effect may originate from the percolation phenomenon. With different annealing temperature (TA) up to 300℃, the saturated Hall resistivity decreased only a little. The good thermal stability of Fe45.51 (Al2O3)54.49 nano-granular Films showed potential application for magnetic sensor.