The microstructural and texture evolution of MgO protective films deposited on Si and glass substrates by ebeam evaporation were investigated. MgO films on both types of substrates consisted of a well developed columnar structure showing < 111 > texture in the cross sectional view and a triangle shape in the plane view. It was found that there is amorphous MgO between each columnar, which occupies 8-25% in the MgO films. The electron energy loss spectroscopy (EELS) spectrum of amorphous MgO showed features of chemical states and electronic structures different from those of crystalline MgO. (C) 2009 Elsevier B.V. All rights reserved.