The generation of orthophoto from remotely sensed images, such as aerial photos, satellite images and airborne scanning images is an important task for various mapping applications. The accuracy of digital elevation model (DEM) data is one of the most important points, which affects the precision of the final orthophotos. So that we want to study the effect of relief on the planimetry .In order to obtain the best resulted Digital orthophoto, which can be used to produce planimetric map. In this paper we will study the generation of digital orthophoto using different DEM approaches. Such as, (field observations using GPS+AT), Photogrammeteric techniques (analytical & digital). This will be followed by some experiments about the quality of the different DEM to get the best results concerning the digital Orthophoto.