We studied the composition and quality of Père David''s deer (Elaphurus davidianus) winter diets in Jiangsu Yancheng Wetland National Nature Reserve, Rare Birds, Jiangsu Province from December 2017 to March 2018 using fecal analysis and direct observation. We surveyed along seven transects (representing four vegetation types) and collected 228 fecal pellets, which formed 14 composite samples. We also collected plants at the foraging grounds to construct a reference library of plant cell morphology, which was used to identify plants in the fecal samples. The frequency conversion method was used to calculate the density of each food resource. The winter diets of Père David''s deer were composed of 51 plant species belonging to 14 families, with Phragmites australis (relative density 23.09%) and Spartina alterniflora (17.58%) being their staples. Other food plants included Suaeda salsa (6.50%), Imperata cylindrical (5.36%), Aeluropus sinensis (4.90%), Festucas arundinacea (3.83%), Scirpus planiculmis (3.45%), Suaeda glauca (3.27%), Puccinellia distans (3.12%), Lolium perenne (2.60%) and Artemisia capillaris (2.60%). Herbs constituted 96.73% of the total forage quantity, with the remainder consisting of twigs and leaves of woody plants. The percentage of crude protein found in the browse was sufficient for the nutritional needs of the Père David''s deer.