Submerged macrophyte plays an important role in lake ecosystems.It is not only a primary producer in the food chain, but also plays a major role in lake nutrient accumulation and circulation,thus,having a great influence on the eutrophication process of lakes.This study reports the seed dormancy and germination of three submerged macrophytes (Potamogeton pectinatus, Potamogeton perfoliatus and Myriophyllum verticillatum) in the Yellow River,located in the Hetao irrigation area of the Inner Mongolia.The result shows: Myriophyllum verticillatum seed has a high dormancy rate,but its dormancy is easy to be broken.Various treatments including seed coat scarification,low temperature stratification,applications of KNO₃ and gibberellin can significantly increase the germination percentages.Potamogeton pectinatus seed has a deep dormancy.Low temperature stratification and application of GA can effectively break the seed dormancy,but other treatments had no effect on.Potamogeton perfoliatus seed has a deep dormancy.None of the above mentioned treatments can significantly break its dormancy.