Abstract: In recent years,with the planning and construction of World Horticultural Exposition Venues,Winter Olympic Venues,Yanqing New Town and Zhongguancun Yanqing high-tech Park,more and more projects will be constructed in the Yanqing Plain Area.During the whole evolution of the Quaternary,the strata in Yanqing area uplifted rapidly and frequently than the Beijing Plain Area,Comparatively,the sedimentary laws are more complex.The main rivers in the area(Gubadaling River and Guguishui River)had experienced reversal of flow direction.As a result,the topographic conditions and groundwater conditions in the study area are complex,the hydro-geological conditions are quite different from those in the adjacent Beijing.The complex hydro-geological conditions have a great impact on the construction of the project in this area.By collecting the relevant engineering geology and hydro-geology background information of the investigation area and combining the groundwater monitoring information of our company in the Yanqing area,the author investigates and studies the hydro-geology conditions of the Yanqing area,and divides the hydro-geology conditions of the area into some hydro-geological zones,so as to guide the relevant engineering construction.