Within the context of Geographical Information Systems (GIS), several types of surface models are being used in a spatial modeling environment. DEM is a fundamental requirement for many GIS applications, both directly due to the influence of elevation on many environmental phenomena and indirectly due to the influence of variables derived from a DEM such as gradient and aspect on environmental phenomena and processes. DEM generated from Survey of India topomaps, ground survey and photogrammetric methods. It is Important to know the expected accuracy of DEM generated from different sources. This study summarizes different DEM methods and the expected accuracy.