Development restriction areas (greenbelt areas) of Korea were recognized in 1970 as a means to control urban sprawl and conserve the natural environment. Although there have been some achievements, for a long time many planners and residents have requested a redefining of the green belt due to individual property rights restrictions and urban management problems. In fact, a lot of the greenbelt area is being destroyed by urban development. Therefore, conservation of ecological spaces in the green belt is needed to maintain urban naturalness. In this regard, this study suggests efficient methods to manage the greenbelt through the adoption of a landscape ecological value assessment. The greenbelt of the Seoul Metropolitan Area (SMA) is represented as the case study because there has been mounting pressure to develop the area in Korea. In this study, the assessment of the landscape ecology in the greenbelt area focuses on landscape structure and function. The assessment consists of the following steps: First, patches were derived by NDVI analysis using landsat remote sensing data. Second, characteristics of the patches were quantified by analyzing the landscape structure, such as patch size and shape index. Lastly, the gravity model and least cost path analysis to assess connectivity were applied to evaluate the landscape function in the green belt areas. The assessment result showed that 48.45% of green belt area should be conserved to maintain ecological stability and function. Moreover, major ecological networks were identified near the large patches in the northern and southern areas. However, relative low ecological values were identified in the western part of the green belt area due to the lack of green spaces. Furthermore, some development plans in the green belt were also identified near the conservation area. Based on these results, the restoration needed areas to enhance ecological value in green belt were displayed. This study suggests efficient management of the greenbelt area, which is disappearing as a result of urban development. The area for conservation chosen in this study should be managed carefully in urban planning. Finally, the results of this study can be used in green belt polices and plans for the promotion of ecological naturalness and stability.