This study reports on a comparison between the Korean diffusion of agricultural innovation or extension service and the cooperative extension service in the United States of America. It focuses on relevant differences between the two systems and provides recommendation for improvement of the Korean system to insure success in important areas related to the diffusion of agricultural innovations. After a comparative study on diffusion of innovations it is clear that: in order to have a productive agriculture that makes effective and efficient use of natural resources and helps achieve sustainability goals, a mechanism that delivers knowledge to agricultural communities must be established and maintained. This mechanism is clearly an agricultural extension service that is cooperatively funded by federal, state and local governments and that insures participation of constituents in the process of establishing priorities and evaluating achievements. The success of US agriculture, the most productive in the world, is to a large degree to the Cooperative Extension Service. Based on the results of this study and the differences of the United States and Korea, the following recommendations should be emphasized for more effective communication for agricultural innovation and rural development in Korea: 1) In order to insure that extension educators are high caliber professional individuals, it is important to establish a system that nationally recognizes these individuals as such, and that provides a professional development path. 2) The results of the decision of transfer of extension educators to local governments has not yielded positive outcomes, especially in terms of professional status. It is clearly demonstrable that valuable professionals are leaving the service, that local governments do not have the will and resources to implement a successful extension program. 3) Because of the critical importance of diffusing innovations to agricultural producers in order to insure and quality and steady food supply, it is of critical importance that these issues be addressed before the extension service is further deteriorated. Given the cement situation, it is clear that the extension service should become nationally supported again in cooperation with local and state governments and that extension professionals be given appropriate rank at the national level, commesurate with their peers in research and teaching. 4) The common current committee practice of lengthy reporting and short discussion needs to be changed to one that results in char, brief and substantive action oriented goals. Joint participation by researchers, extension educators and farmers should be encouraged in planning, implementation and evaluation of communication for agricultural innovations. Roles and functions of committees for institutional cooperation, and or agricultural extension committees should be enlarged. 5) Extension educators should be encouraged to adopt new communication technologies to improve their diffusion of innovations methods. Agricultural institutions and organizations should be encouraged to adopt farmer-first and or client-oriented approach in agricultural extension and diffusion of agricultural technologies. The number, complexity and rapid change of information in agricultural extension require the development of a computer based information and report system to support agricultural extension. 6) To facilitate and expand the further development of communication for agricultural innovation and rural development, agricultural communication programs in universities especially in colleges of agriculture and life sciences. 7) To strengthening the sense of national and social responsibility communication for agricultural innovation and rural development among students in agricultural colleges and universities through participation in learning activities by proactive recruitment. 8) To establish and reinforce a policy that insures participation..