HfSixOy thin film has been prepared by using radiation frequency (RF) magnetron sputtering. The influence of process parameters on the deposition rate of HfSixOy film was studied systematically. The structures of as-deposited HfO2 and HfSixOy films have been investigated, and analyzed for the films after annealing. The results show that the deposition rate of HfSixOy film increases with the increase of RF power, Ar gas flow and area of Si, while decreases with the increase of sputtering pressure. The results of structure analysis show that the as-deposited HfO2 and HfSixOy films deposited at room temperature are amorphous. With the substrate temperature increasing, the HfO2 film crystallizes but HfSixOy film is still amorphous. The HfSixOy film remains amorphous after annealing at 800 ℃ but HfO2 thin film crystallizes obviously after annealing at 400 ℃. It indicates that the thermal stability of HfSixOy thin film is better than that of HfO2 film