The work aims to control wetting behavior of anodic aluminum oxide (AAO) film surface by chemical grafting methyl methacrylate on anodic aluminum oxide (AAO) film surface and changing roughness and molecular structure of the surface. Highly nanoporous ordered AAO film was fabricated in a two-step anodization method. The structure of nanoporous AAO film featured in close-packed hexagonal arrangement of approximately hemispherical concaves. Surface of the nanoporous AAO film was further treated with 3-Methacryloxypropyltrimethoxy (KH-570). Then, the AAO film modified with poly(methyl methacrylate) was prepared by grafting methyl methacrylate onto the surface of nanoporous AAO film in the method of living polymerization. Structural characterization and wetting behavior study were performed to AAO film and modified AAO film using atomic force microscope (AFM), X-ray diffractometer (XRD) and contact angle tester. Effects of anodizing process conditions and methyl methacrylate grafting on morphology and wettability of AAO film were investigated. The nanoporous AAO film was amorphous, its pore diameter was about 100 nm, and hexagonal holes were well distributed in parallel and perpendicular to the surface of AAO film. Water contact angle of the AAO film first increased and then decreased by grafting methyl methacrylate. The wetting behavior of AAO film surface can be controlled by chemical modification of AAO film surface and surface roughness together.