Found in 23 Dec 1953 to cope with illegal fishing of foreign ships and coastal guard duty, Korea Coast Guard was re-organized as an office under Ministry of Public Safety since the outbreak of sinking of passenger ship "Sewolho". In the course of re-organization, intelligence and investigation duty were transferred to Police Department except "Cases happened on the sea". But the definition of intelligence duty is vague and there are lots of disputes over the jurisdiction and range of activities. With this situation in consideration, the object of this study is to analyse legal and institutional characteristic of KCG Intelligence, to compare them to that of Police Department, foreign agencies like Japan Coast Guard and US Coast Guard, to expose the limit and to suggest solution. To summarize the conclusion, firstly, in the legal side, there is no legal basis on intelligence in [The Government Organization Act], no regulation for mission, weak basis in application act. Secondly, in the institutional side, stated in the minor chapter of [The Government Organization Act], 'the cases happened on sea' is a quite vague definition, while guard, safety, maritime pollution duty falls under 'on the sea' category, intelligence fell to 'Cases happened on the sea' causing coast guard duty and intelligence have different range. In addition, reduced organization and it's manpower led to ineffective intelligence activities. In the case of Police Department, there is definite lines on 'administration concerning public security' in [The Government Organization Act], specified the range of intelligence activities as 'collect, make and distribute information concerning public security' which made the range of main duty and intelligence identical. Japanese and US coast guards also have intelligence branch and performing activities appropriate for the main missions of the organizations. To have superiority in the regional sea, neighboring countries Japan and China are strengthening on maritime power, China has launched new coast guard bureau, Japan has given the coast guard officers to have police authority in the regional islands, and to support the objectives, specialized intelligence is organized and under development. To secure maritime sovereignty and enhance mission capability in maritime safety duty, it is strongly recommended that the KCG intelligence should have concrete legal basis, strengthen the organization and mission, reinforce manpower, and ensure specialized training administrative system.