The objectives of this study were to review on the characteristics of the Agricultural Research-Extension Systems in the USA, Japan, and the Netherlands, and to draw up its implications on Korean agricultural extension system. This study was conducted by literature reviews. Based on the reviews, the following implications and recommendations should be considered at national and local level for improvement of agricultural extension system in Korea; (1) a systemic approach on the linkages of agricultural research, extension, and farmer education, (2) strengthening on-farm utilization of newly developed agricultural technology so as to promote agricultural research and development, (3) strategic partnership with agricultural administration, (4) close networking with stake-holders, (5) setting up the flexible organizational structure for carry out agricultural extension programs, (6) integration of agricultural extension service domain, (7) introduce a IPM(integrated performance management) system, (8) establish a long-term super-vision and strategic management, (9) setting up the customer-centered extension system.