Oxidation at high temperature of Ti/TiAl microlaminates prepared by electron beam physical vapor deposition technology was studied in this paper, and then the alteration of phase structure was analyzed by X-ray Diffraction (XRD), the surface topography and composition were observed by Scanning Electron Microscopy (SEM) and Energy Dispersive Scanning(EDS). The results show that with temperature increases, diffusion velocity of Al element into Ti zone develops more and more quickly, and blending phenomenon gets more obviously. The oxidation mechanisms of Ti/TiAl microlaminated sheet at high temperature is that the Ti contents in each component layer increase gradually with the constant diffusion of Ti atoms towards surface. Al2O3 and TiO2 has the advantage of thermodynamics and dynamics growth respectively. The combined action of the two aspects lets the Al2O3 oxide film change to the (TiO2 Al2O3)and TiO2 oxide film gradually.