The Fen river is the longest river in Shanxi province and the second longest tributary of the Yellow River. In history，as the Shanxi people’s mother river has benefited the land of the three Jin with the benefit of irrigation and river transportation. Later，the settlement，deforestation and industrial waste water pollution，caused drought in Shanxi province frequently，intensified soil erosion，forest vegetation destroyed constantly. Production and life are affected. In order to implement the spirit of General Secretary Xi Jin ping’s important speech at the symposium on ecological protection and high-quality development of the Yellow River Basin in Zhengzhou，it is urgent to discuss the ecological changes of the Fen River Basin and draw lessons from history. This is very beneficial to the protection of precious water and soil resources and the high-quality development of economy and society of Shanxi province.