This paper describes the evolutionary trajectory of the missions of public research institutes(PRIs) in Korea since 1960s and analyses the newly highlighted role of PRIs as the facilitators of regional innovation system, with questionnaire surveys and the case study of Gwangju Institute of Science and Technology(GIST). PRIs have played important roles in Korean rapid economic development by introducing and improving foreign high-technologies in 1970s and 1980s and by creating new advanced high-technologies in 1990s. In recent years, the functions as regional technology innovators have been considered important as regional innovation system has come to the center of discussion. According to the result of this study, Korean PRIs have recognized their roles relevant to regional innovation, such as developing the technologies of regional strategic industries and awakening regional innovative actors to a sense of research. Regardless of the functions as industrial technology suppliers, however, the bilateral networks between PRIs and regional industries are not revealed strong, whereas those with universities and other research institutes are relatively strong. In addition, the research cooperation of PRIs with regional innovative actors are different by where they are located. The case of GIST shows how a regional PRI operates, commercializes its academic achievement and encourages the regional transfer of the achievement systematically. Finally, this study draws some policy implications on developing regional PRIs.