Abstract: Water level can be used as an important ecological variable to indicate the growth and propagation of wetland plants. It has effects on the plant community composition and species biodiversity. Water level fluctuation is a crucial factor to shape the primary productivity, biodiversity and structure of aquatic macrophyte community in the wetland. Poyang Lake is the largest shallow river-connected lake in China, with significantly seasonal water-level fluctuation affected by the floods and drawdown of the Yangtze River and other inflowing rivers. This study explored how the water-level fluctuation affects the aquatic macrophytes in Poyang Lake. The adaption strategies in response to submergence and emergence were also investigated. The study was conducted through the lake investigation in three water regime periods (high-water period, normal-water period and low-water period) from 2009-2010. High water level gave rise to the complete submergence of wetland plant species such as phreatophytes, hygrophytes and hydrophytes, in Poyang Lake during the high-water period. The phreatophytes were stressed by high water-level mainly adopted either dormancy or tolerance (termed as quiescence) strategy to pass through this adverse time. Meanwhile, submersed and floating-leaved plants were rich in the wetland, and the dominant species were Potamogeton malaianus, P. maackianus, Vallisneria natans, Hydrilla verticillata, Ceratophyllum demersum and Nymphoides peltata. The records of the lowest water level had been broken in Poyang Lake during the low-water period, and drawdown was greatly brought forward within one month. Water level regime was broken markedly in low-water stage of Poyang Lake. The phreatophytes in bottomland also germinated early about one month. Phalaris arundinacea, Carex cinerascens, Artemisia selengensis, Polygonum hydropiper, Leptochloa chinensis and P. criopolitanum dominated in the bottomlands, and meso-hygrophyte species were dominant in middle-and high-level grasslands. The bottomlands of Poyang Lake were partly inundated with the clear gradient of water-depth during the normal-water period in March of 2010. In this period, the overground biomass of the dominant phreatophytes species of Carex (e.g. C. cinerascens, C. scabrifolia) and P. arundinacea manifested the statistically significant variations along the gradient of water depth.