Structural and optical properties of pure Mg thin film coated with Pd have been investigated. Pd-capped Mg thin films had been prepared by DC magnetron sputtering. This work presents an ex situ study on hydrogenation and dehydrogenation kinetics of Pd/Mg films at different conditions using XRD, AFM and optical spectrophotometer. We have succeeded to load thin films of Mg to MgH2 at normal temperature and normal pressure of hydrogen gas. In hydrogenation, alpha-MgH2 phase of magnesium hydride was observed in hydrogenated films at 200 degrees C and gamma-MgH2 at 250 degrees C respectively. The desorption kinetics in vacuum also revealed the phase transformation alpha-MgH2 to gamma-MgH2. A reflectance change was observed in hydrogenated films in comparison of as deposited thin film. Hydrogenated ( H loaded) samples were observed partially transparent in comparison of as deposited. (C) 2011 Elsevier B. V. All rights reserved.