Abstract: The morphology of CuPc/ITO sample was investigated using Atomic Force Microscopy（AFM）.It is found that CuPc molecules cover the surface defects of ITO and form a uniform film with few pores.The fact is further testified by XPS investigation on the surface and interface of the sample.And it also shows that CuPc film can prevent chemical constituent in ITO diffusing into hole transport layer.The property and life time of OLED devices are improved.