Winter buds of submerged macrophytes are main food for herbivorous waterfowl in winter. Poyang Lake is important wintering sites for waterbirds in the Yangtze basin. Understanding the spatial distribution of winter buds and their food contribution for herbivorous waterfowl can provide scientific basis for waterfowl conservation and lake management. We studied species composition, individual density, and spatial distribution of winter buds using quadrate method in October 2012 and April 2013 in Shahu Lake, a sub-lake of Poyang Lake. Winter buds of two submerged plant species, Vallisneria spinulosa and Hydrilla verticillata var. rosburghii, were recorded. The average density of winter buds of Vallisneria spinulosa was (9.53 ± 1.73)ind/m² and of Hydrilla verticillata var. rosburghii (25.78 ± 3.97)ind/m² in October, which were also significantly higher than that in April ((2.52 ± 0.91)ind/m² for Vallisneria spinulosa and (4.76 ± 1.17)ind/m² for Hydrilla verticillata var. rosburghii)(Z=3.712, P < 0.01 and Z=5.738, P < 0.01, respectively). The average biomass of winter buds (dry weight)of Vallisneria spinulosa was (3.07 ± 0.65)g/m² and of Hydrilla verticillata var. rosburghii (5.43 ± 0.75)g/m² in October, which were significantly higher than that in April ((0.89 ± 0.35)g/m² and (2.21 ± 0.59)g/m², respectively)(Z=3.118, P < 0.01; Z=3.821, P < 0.01). The density of Hydrilla verticillata var. rosburghii winter buds was significantly higher than Vallisneria spinulosa winter buds in October (Z=3.466, P < 0.01)while there was no significant difference in the density of the two species of winter buds in April (Z=1.677, P=0.09). The average depth that suitable for the formation of winter buds of the two species of submerged plants was (2.63 ± 0.15)m and (2.61 ± 0.12)m, respectively, in flooding season (from April to September). Winter buds of Vallisneria spinulosa and Hydrilla verticillata var. rosburghii are important food for herbivorous waterfowl in Shahu Lake. It is estimated that waterfowl consumed 1.04×10⁸ ind (1.9×10⁴ kg)of the two species of winter buds in winter.