A 3, 4-dihydroxyphenethylamine (dopamine) polymer film has been prepared on copper surface from 2.0g/L dopamine solution in tris(hydroxymethyl)aminomethane hydrochloride (Tris-HCl) buffer solution at pH 8.5 by a simple solution-immersion method. The dopamine self-polymerized and adhered to the copper surface firmly in aqueous environment. The film surface was evaluated through SEM, EDS, XPS and contact angle measurement. The results have shown that the film was indeed formed on copper surface. And this research offers a versatile approach for the surface modification.