The preparation method and stalic property of phase change optical storage Ge 2Sb 2Te 5 thin film have been analysed. After measuring its static properties, we found that the Ge 2Sb 2Te 5 film can be written and erased within 100 ns. Through multilayer design, the write/erase cycle numbers can be as high as 10 6, and the reflectivity contrast is above 15%.