Abstract: This study used remote sensing and GIS to analyze the landscape pattern changes in the Yancheng Nature Reserve from 1983 to 2018, established an evaluation index system based on the regional natu-ral-socio-economic complex ecosystem security pattern, and then analyzed the spatial characteristics of eco-logical security changes and discusses reasons for these changes. The results show that the landscape pattern changed dramatically from natural landscape to a mixture of natural landscape and artificial landscape from 1983 to 2018 due to the intensification of human activities. At present, the ecological security status of the protected areas is not optimistic. From the perspective of the survival status of red-crowned cranes, the protected areas are suitable. However, due to the increase of human activities and policy adjustments, the habitat of red-crowned cranes is fragmented. The red-crowned crane currently gathers in localized areas such as the core area and the buffer zone. We should pay more attention to management, policy development and the environmental awareness of local residents. At the same time, it is necessary to reduce the intensity of human activities within the reserve.

Key words: ecological security assessment, pressure-state-response (P-S-R) model, analytical hierarchy process (AHP), index weight, Yancheng Nature Reserve