In my project, I researched the boundary in the field of architecture. I suppose that setting the boundary is the most primitive architectural activity. It is often said that the beginning of architecture was constructing the roof to prevent from rain. When the roof is constructed the boundary between inside and outside is generated. Setting boundary in space is, so to say making order in disorder or giving concreteness to abstraction. A boundary divides the space into two. However, the divided two spaces share a boundary. Therefore I think when the idea of “dividing” comes up we can always find a sense of “sharing” as well. As a starting point I believed that when the notion of “connecting” is added to boundary there could be a new value in the space. I surveyed how the idea of setting boundary in architecture has been changed through history. In my research I reached the concept of “gradational boundary” which divides a space but also connects the space at the same time. Furthermore I designed a piece of furniture which functions both as a shelf and as a room divider based on this concept.