MgAl Layered double hydroxide (LDH) films were synthesized on an anodized magnesium alloy using the anodized layer as internal feedstock of cations. The morphology and composition of as-prepared the LDH films were investigated. The results showed that a compact and uniform LDH was formed on the anodized substrate. EIS showed that the films with bilayer structure significantly enhanced the impedance of anodic films, indicating an effective protection for magnesium alloy. (C) 2017 The Electrochemical Society. All rights reserved.