AbstractIn line with the fact that carbon dioxide capture and storage (CCS) technology has been regarded as one of the most promising option to mitigate the climate change and global warming, we have started a 10-year R&D project on CO2 storage in marine geological structure. We carried out relevant studies, which cover the initial survey of potentially suitable marine geological structure for CO2 storage site, monitoring of the stored CO2 behavior, basic design for CO2 transport and storage process including onshore/offshore plant and assessment of potential environmental risk related to CO2 leakage in storage site. The purpose of this paper is to introduce and review the latest progress on the development of technologies for CO2 storage in marine geological structure and its perspective application in republic of Korea. At current stage, sub-seabed geological storage at ocean region is technically more feasible and economically attractive CO2 disposal option. Therefore, we try to capture CO2 from major point sources (eg., steel making industry and power plant) and transport CO2 for long-term storage into the marine geological structure in coastal area around the Korean Peninsula.We developed Korean technology roadmap for CO2 storage in marine geological structure and carried out collaborative basic and detail researches to demonstrate the feasibility of CO2 storage with national research institute and university groups. By using the results of the present researches, we can contribute to understanding not only how commercial scale (about 1 Mt CO2) deployment of CO2 storage in the marine geological structure of East Sea, Korea, is realized but also how more reliable and safe CCS is achieved.