Submerged plants are important components in lake ecosystems, their production and distribution pattern are affected by environmental factors, especially the hydrologic regime. Lake Dongting is an important large lake in the Yangtze River Basin with free hydrologic connection to the main stream. In recent years, due to influences of human disturbances and climate change, environmental factors such as hydrologic regime and water quality of Lake Dongting have been changed dramatically, resulting in the decline of submerged plants, which calls urgent science-based rehabilitation. Thus, there is a need to have further study on submerged plants at Lake Dongting. In this study, West Lake Dongting was selected as the research area. Submerged plant communities and 12 environmental indicators were investigated in 98 sampling plots at 11 sites in West Lake Dongting during summer in 2018 and 2019. Independent t-test and redundancy analysis were used to evaluate the relationship between the submerged plants and environmental factors, and to explore the effects of hydrologic regime change on submerged plants between years. Results showed that: 1) Submerged plants in West Lake Dongting were mainly distributed at semi-isolated sub-lakes or free flooding lake bays where with shallower water depth, better water quality and more stable water body, whilst there is less distribution at sites in major flowing channels and with high water fluctuation. Water depth, transparency, total phosphorus in bottom sediment and water pH showed significant differences between sites with and without appearance of submerged plants in West Lake Dongting; 2) Biomass of submerged plants was significantly correlated with pH, water depth and total phosphorus in water; 3) At free flooding lake bay, biomass of submerged plants was higher in 2018 than it in 2019. It is supposed to be the result of water level raising processes during May to August 2019 when was key growing stage of submerged plants. A continuously high-water level adversely impacted plant growth. Maintaining natural hydrologic regime, habitat heterogeneity with free flow in the lake, and healthy water quality were proposed to be the key factors to rehabilitate submerged plants in the West Lake Dongting. Sites at free flooding lake bay or semi-isolated sub-lakes those with water depth less than 3 meters, appropriate water nutrients, low water flow rate and less waves were recommended to be rehabilitated in priority.