This study is to establish the Incheon Metropolitan City Arboretum Development Plan (IMADP) as a capacity building both for plant diversity conservation and nature friendly leisure activity areas of Incheon Metropolitan City, Korea. The arboretum planning area is located within territory of the Incheon Grand Park Based on the IMADP, the arboretum was divided into three display spaces; the Urban Greening Garden, the Rare and Endangered Plant Species Garden and the Theme Garden. Detailed planting guidelines were suggested according to the three garden areas. The Urban Greening Garden was designed to display the following three; the relevance techniques, the model, and the practical uses of plants that are regarded to an urban greening. The Rare and Endangered Plant Species Garden (REPSG) was planned for the collection and display of the rare and endangered native plants in the territories of Incheon and the island seashore. Also, the REPSG includes the education purposes of comparing and displaying taxonomically related plant species. The Theme Garden was projected for the collection and display of plant species that have long been familiar to Korean culture and which are also used in our daily life.