I know one way to solved it, by go to the picture properties-->picture tab.
But i try to find a way do it with arcpy. Is it possible?
Sounds like you just want to change the source of the image. You need to use
ListLayoutElements on your MXD. From the help:
import arcpy mxd = arcpy.mapping.MapDocument(r"C:\Project\Project.mxd") for elm in arcpy.mapping.ListLayoutElements(mxd,"PICTURE_ELEMENT", "*logo*"): if elm.name == "CityLogo": elm.sourceImage = r"C:\Project\Data\Photo.bmp" mxd.saveACopy(r"C:\Project\Project2.mxd") del mxd