This research study the cause failure earth dams After that it show the more important problems which dams exposure. During its construction and compassingthe importance causes of this case and how we can processing it , and show also the necessary of earth dams observerand the necessary reportsto showing that the work of dam is good. The research also discusses the analysis of earth dam using the Geo slope program. We have chosen many parameters as total stresses, vertical strain , and pore water pressure to study change of this parameters with elevation in the upstream , downstream , and core of dam and draw the requisite graphsgraphs to compare this design values with reading of observer devices to be sure of typical work of dam. Finaly we showing the results and suggest many recommendations.