Cloud computing is the modern operational model of the enterprise recourse planning (ERP) systems, almost of the major ERP providers such as Google, SAP, INFOR and others began to provide Cloud ERP services to attract a new clients specially small and medium enterprises (SME). Many researchers focus on the benefits that organization will obtain when they move from managing their own ERP system to use the Cloud computing as an operational model for the ERP services. Our goal in this paper is to explore the challenges of adopting cloud ERP services.