The main objective of this study is to find out the factors influencing the usage of E-banking in Ethiopia. The study tries to find the main independent variables that could hamper the development of E-banking service products based on the two widely used adoption theories which are Technology Acceptance Model (TAM) and Innovation Diffusion Theory (IDT). The study identify main independent variables (perceived usefulness, perceived ease of use, compatibility, complexity, triability, observability, perceived risk or trust, culture, awareness,rninfrastructure, legal framework and government support) and usage or practicing of E-bankingrnservice products as dependant variable. Data on bank clients was collected in Addis Ababa from one government bank, Commercial Bank of Ethiopia and three private banks, Awash Bank, Dashen Bank, and Bank of Abyssinia and random quota sampling was taken from each of these banks. The analysis of data was made through SPSS 20. The study found out that the above independent variables have their own effect on the development of E-banking but infrastructure and compatibility have more weight. Much have been said in other studies about the poor level of infrastructure. As it is discussed on literature review part, Ethiopia is rated at the lowest even compared to East African countries. This study give attention to compatibility that is the need for integration of E-banking systems of all banks in Ethiopia and having one national platform in order to develop E-banking, E-commerce, E-marketing as well as Digital Economy.