Mg-Al layered double hydroxide (LDH) film and Mg-Al LDH film intercalated with 8-hydroxyquinoline-5-sulfonic molecules (HQS) was formed directly on magnesium alloy AZ31 by in situ growth method using a hydrothermal treatment. The crystal structures and d-spacing of the LDH were estimated by XRD measurement. FE-SEM studies revealed that all the samples exhibit nanosheets that are aligned at fairly inclined angles with respect to the surface. Some rosette-like structures can be observed on the HQS molecules contained LDH surface. Potentiodynamic polarization curve measurements revealed that the corrosion resistance of the HQS intercalated LDH film coated magnesium alloy was greatly improved compared with the untreated magnesium alloy and the LDH film coated magnesium alloy.