There are eight chapters in this thesis. Chapter One deals with current literature on curriculum implementation, which in a way helps as a theoretical framework. Chapter Two deals with methodological issues, and research questions asked. This involves discussion of qualitative case study design for studying issues of educational policy formulation, curriculum development, and implementation at school level. Chapter Three presents a brief historical account of the changing pattern of curriculum in Ethiopia with particular emphasis on the purpose of education, context of curriculum implementation, and practices of teaching & learning at different historical and political periods in the country Chapters Four to Six present three case studies: the case of the process of policy formulation and curriculum development in Ethiopia, and two cases of curriculum implementation at school level. They describe the background, the nature, and process of policy / curriculum development in Ethiopia and the reality of implementation at school level. Chapter Seven is a cross-site analysis of the key issues emerged out of the three case studies. This focuses on issues to do with top-down and `teacher proof nature of the reform, teachers' and principals' attitudes and practices, factors limiting and assisting implementation, and the implementation gap between the top and the bottom. Chapter Eight sets out a number of conclusions and implications with respect to each research question. It recognized the process of curriculum development and implementation as highly social phenomenon, which cannot be mandated, and as something that should be owned with belief, commitment, and capability for real change to happen. Furthermore, the cross-site analysis supports the literature on the area that the exclusive top-down approach to educational policy formulation and curriculum development inherently and logically has serious flaws to implement educational innovations at school level.