In order to make an effective use of spatial resources in the city, detailed environmental plan strategies based on 'culture' are needed. An integral part of city spaces-'underground space' serves as one of the spatial resources with much effective usage potentials. Hence, 'underground space' needs cultural vitality. The purpose of this study is to propose an thorough indoor environmental plan guideline for the cultural vitality of 'underground space'. The methods used to conduct research include precedent study reviews and survey. Through this research, following conclusions are drawn. First, to promote cultural vitality at the 'underground space', it must be transformed into the cultural public place to be utilized for cultural activities by residents. Second, the 'underground space' requires 'concept of eco-friendly space for clean environment'. Third, 'safe environment' concept must be installed in the 'underground space' to promote the cultural vitality. Fourth, the 'underground space' requires 'complex/block level network plans between cultural spaces in addition to horizontal/vertical walking network between cultural environments in ground level and underground spaces. Fifth, the 'underground space' requires underground public cultural space plan through 'reasonable underground development with considerations of the facilities related to education, culture and history'. Sixth, 'public cultural space plan for various cultural spaces' and 'supply of space for cultural activities for residents and design plan for mutual culture exchange' are necessary.
