This study was conducted to suggest the ways of improving legislative information services in the National Assembly Library based on the information needs of the legislative support organization arising from the legislation process done by the National Assembly Members. For the purpose, 20 users of legislative support organizations were interviewed in depth. Based on the analysis of the results, the study suggested the improvement proposals in the areas of services and system. Service improvement reflected the information needs of overseas legislative cases, the need for supplementing policy information, and the areas that need to be promoted Second, in the area of system improvement, it was proposed to raise the service awareness of the legal information system centered on foreign legal information and to operate personalized service that can provide differentiated information services for each legislative support organization.