Abstract: The Bay Area, the most concentrated area of human activities, has obvious advantages of location and industrial clusters. As a frequent interaction zone between sea and land, the ecological environmental problems in this region are particularly prominent under rapid urbanization process. Based on the evaluation results of resource and environment carrying capacity and suitability of territorial space development in Fujian Province, we have conducted 1DK:50 000 geological environment survey of important ecological elements within the ecological service function zone and ecological problem risk zone in Minjiang Estuary. Guided by the concept of Land-Sea Coordination, we added such important evaluation indexes of ecological protection in "Double Evaluation" in accordance with the reality of the Bay Area as coastal hills, sandy coastline shelterbelt and uninhabited low cover-rate island. A "Double Evaluation" method and technology system for Land-Sea Coordination in the Bay Area has been established, and the ecological conservation importance of Mingjiang Estuary evaluated. The ecological security development pattern of Mingjiang Estuary has thus been constructed, which will provide theoretical and basic support for the green and high-quality development of the Bay Area urban agglomeration. Our research indicates that:The first mountain in the coastal area is an important ecological protection shield for the Bay Area, playing an irreplaceable role in the coastal cities' resistance to typhoons and desertification erosion; Islands are related to national maritime rights and interests. The smaller the area, the worse the vegetation coverage, and the farther the uninhabited islands are from offshore, the higher the ecological security risk will be. The coastal zone is where land and sea interact. It is a significant area for the development of coastal cities, and also a key area connecting ecological patches of land and sea. Its ecosystem is more fragile than that of land area, so more stringent ecological security protection measures should be implemented for areas prone to soil erosion and shoreline siltation. Coastal bare rock with medium-coarse-grained granite lithology is a high-prone area of soil erosion and a risk area of shoreline siltation.