this thesis explores the miyun reservoir watershed’s soil condition and the current situation it faces now. miyun reservoir is located in northern beijing and has more than sixty years of history. it is the primary water source in beijing and was listed as a first-grade water source protection in 1985. the reservoir has a maximum surface area of 188 square kilometers, and it is shaped like an equilateral triangle. for a better sustainable development, the government and each department began to plan and survey miyun reservoir in 1951. nowadays, the scale of watershed treatment development is getting bigger and bigger, and this place has received more and more attention. by doing literature reviews and analysis from the database, this thesis discusses the factors that affect the soil condition changes in various watershed compositions, such as land-use types, soil properties, soil organic matters, topography, and water areas. different components can affect soil moisture, chemical elements in soil, and the degree of soil erosion from all aspects. at the same time, it also faces the pollution problems, which leads to a decrease in water quality and balance of the ecosystem there. more policies are implemented in the miyun reservoir, and it becomes more and more important for better environmental protection and tourism development.