Yongding River is the mother river of Beijing. Due to the terrain, the Yongding River Basin has been flooded repeatedly in history, so the name of the river is associated with the desire to avoid disasters and live a stable life. There are a large number of legends about the Yongding River in the Yongding River Basin. The basic feature is that the legends are connected with historical facts, and the shadow of history is reflected in the legends. Among the many legends, the most representative ones are "The Legend of Hedangdang River", "The Legend of Shijing Mountain and Shijing Mountain", "The Legend of the Water Buffalo in Yongding River Town", "The Legend of Old Man Wang Planting Willows on the Riverbank", "The Legend of General Feng Punishing the Old Soldier Ruffian", "The Legend of the Origin of Mayu Village", "The Legend of Liu Niangfu", etc. The legend of Yongding River is vivid, rich in content, and has a strong local color. It is the crystallization of the wisdom of the people on both sides of the Yongding River. It records the history of people's governance of the Yongding River and provides detailed information for the study of the production development history of Beijing. The spirit of the people around the Yongding River to fight against nature in order to subdue the floods reflected in the legend also has certain practical educational significance. At present, a large number of inheritors of the Yongding River legends in Beijing's Shijingshan District are all elderly. If they are not recorded and organized as soon as possible, the long-standing Yongding River folk legends may gradually decline under the impact of modern entertainment culture, and eventually disappear with the passing of the storytellers.