Abstract: The Yancheng Nature Reserve (YNR) is an important wintering ground for wild red-crowned crane (Grus japonensis) in the world on their migration route. Recently, the wintering ground of YNR has undergone significant changes. An analysis was done of changes in the wintering habitat of red-crowned cranes in YNR during the period of 2000-2013 and their major causes, using the MAXENT Model, data of field surveys, and environmental characteristic variables extracted from Landsat 5 TM and Landsat 8 images of 2000 and 2013. The analysis reveals that the distance to roads, fishponds and smooth cordgrass (Spartina alterniflora), and the distance to reed shoals and seepweed shoals, as well, were the main factors that influenced selection of wintering habitat by red-crowned cranes in 2000 and 2013, respectively. During the period of 2000-2013, suitable habitats for red-crowned cranes decreased from 94 571 to 22 365 hm² in area, and were getting more and more fragmented. The distribution of red crowned crane habitats changed in pattern, from a continuous one to one concentrated around the core area of YNR. The loss of suitable habitats may be related to drastic reduction of seepweed tidal flats, mudflats and salt pans in area, and rapid expansion of fish ponds. It is, therefore, recommended that more efforts be devoted to the following aspects of work in protecting red-crowned crane habitats in YNR:(1) strengthen protection and restoration of the wetland habitats in the core area; (2) intensify management and conservation of the artificial wetlands in the buffer area and the experimental area; and (3) enforce supervision and management of human disturbance activities in YNR.