Humans acquire more than 80 percent of information by eyesight, which requires light to recognize objects. That makes lighting for museums and art galleries one the of the most critical exhibition conditions. Art lighting can be done with natural light or articial light. In Korea, where museums and art galleries have grown in numbers as public entertaining facilities since the 1980s, natural lighting has been more employed than artificial one to enhance exhibition conditions. However, natural lighting has been cautiously adopted because it can damage art works and it is highly likely to fail without high technology and ample funds. As an environmentally-friendly factor for enhancing exhibition conditions, natural lighting for museums and art galleries is employed not only in exhibition halls but also in transitional spaces like passageways, lobbies and vestibules. Given the fact that sun light varies depending on the season and daily weather, lighting designers should install devices that can control the amount of light. They also should adjust the source of light to maintain the color temperature that determines the atmosphere of artifacts. In addition, they should ensure that the color temperatures in one exhibition hall are balanced and should know color rendition levels of artifacts depending on the source of light to allow the artifacts to be exhibited in their natural colors. Moreover, they also should place devices that can block ultraviolet rays from raising indoor temperature, from dazzling visitors and from damaging artifacts on display. Natural lighting has advantages in many respects. In terms of management, it significantly reduces energy cost, especially in taransitional spaces like passageways and grand spaces like lobbies. In terms of exhibition environment, it allows visitors to retain their sense of direction and keeps them from feeling lost in a maze by enabling them to keep in touch with outside. In addition, natural lighting also relieves visitors of eye fatigue. On the other hand, natural lighting can be employed in a way that brings damage to a minimum: when natural light is employed only for artworks insensitive to light; when illurnination levels are fixed according to the objects on display. Natural lighting has been considered counter to conservation. However, it should be adopted especially for transitional spaces to ameliorate exhibition conditions and for modern sculpture works to let visitors view the artworks in different respects depending on changing light. Moreover, natural light can be more efficient1y used if museum designers consider natural lighting from the early stage of construction. Museum visitors should not be deprived of their pleasure for the sake of conservation and artifacts also should not be damaged for the sake of effective display. In short, effective display and conservation should be balanced. In conclusion, natural lighting should be promoted for enhanced exhibition conditions but also should be cautiously employed for the sake of conservation. In doing so, further and deeper research should follow.