A method of synthesizing novel anodic alumina films with antibacterial property is presented. The process includes preparing a film by anodic oxidation of aluminum and subsequently introducing silver to the films. The antibacterial effect of such a film was estimated by in vitro tests. Escherichia Coli and Staphylococcus aureus were chosen as bacteria to test the antibacterial capacity of such films. It is found that the antibacterial effect was achieved by releasing of silver ions and the effect could be lasting for more than 24 months in atmospheric condition. Scanning electron microscopy was employed to survey antibacterial film. The chemical state of silver in the films was analyzed by X-ray photoelectron spectrum, and Auger electron spectrum was performed to determine the concentration of silver atoms in various films. Ions releasing experimental was carried out in water and the mixture of water and dilute nitric acid, the amount of silver ions releasing from the film was measured, and the total amount of silver in the films was more than 0.13 mg. This antibacterial film can be widely applied and its antibacterial effect maintained for a long time.