PURPOSE: A black coloring method for an aluminum anodic oxide film is provided to prevent environmental contamination by employing tannin aqueous solution for coloring and form a black film with superior light fastness. CONSTITUTION: A black coloring method for an aluminum anodic oxide film includes a step of dipping an aluminum anodic oxide film in tannin aqueous solution containing iron ion. The tannin aqueous solution comprises tannin 5~100 g/L and iron ion 5~100 g/L. The temperature of the tannin aqueous solution is maintained at 20~70°C so that the reaction between tannin and iron ion is optimally activated and the coloring of the film is rapidly completed.
