The Tarim red deer (Cervus hanglu yarkandensis) is a flagship species dwelling the Euphrates Poplar (Populus euphratica) riparian forests along the Tarim River. The wild population is listed as a first-level protected species in China. At present we miss information about , it is unclear the seasonal variation of its foraging ecology in this environment dominated by interspersed Euphrates Poplar forests and cotton (Gossypium hirsutum ) crops in Shaya, Xinjiang. We used DNA metabarcoding technology to investigate the diet of the Tarim red deer in both summer and winter during 2021-2022. We targeted chloroplast gene trnL (c-h) region for plant identification. From a total of 39 fecal samples analyzed, we identified 50 plant species, In term of frequency of occurrence, main feeds were cotton (38.75%), and Euphrates Poplar (36.87%). Other plants were occasionally present: Phragmites australis (7.00%), Halimodendron halodendron (6.13%), Chenopodium album(4.67%), Glycyrrhiza inflata (3.50%), Kalidium gracile (0.28%), Glycyr-rhiza glabra (0.25%), Myricaria bracteata (0.16%), Dodartia orientalis (0.07%). Deciduous trees (36.87%) and shrubs (45.98%) represent the main food categories, followed by forbs (9.74%) and graminoids (7.11%). As expected, the Shannon and richness index, was signifi-cantly higher in summer than in winter (p < 0.05), and the dietary niche width in winter was significantly lower than in summer (p < 0.05). Overall, our results indicate that the Tarim red deer is a seasonally-adaptable mixed-feeder. This study provides essential data for a better un-derstanding of the foraging ecology of Tarim red deer. Further it provides evidences to improve its management and conservation.