Research and extension are the main pillars of agriculture system and their effectiveness largely depends on strong linkage among each other. This paper is organized with specific objective of contributions and challenges in Research and extension linkage for agricultural transformation in Ethiopia. As different data approve that, the existing research-extension linkage is weak in Ethiopia. This very weak linkage has been major limiting factor in increased food productivity, agricultural transformation and sustainable development. Its well-coordinated and strong linkage can facilitate agricultural commercialization, promote sustainable agriculture and help to dissemination of useful Information. But it is mainly constrained with weak organization system, poor Infrastructural, lack of incentives for linkage activities, lack effective motivation system, poor communication, personal and psychological skills. So, government and any concerned bodies should be invested on establishing strong linkage between research-extension, improving infrastructural facilities, professional skills of extension staffs and should be established better salary, motivational techniques, monitoring and evaluation system.