Aridification in northern China is one of the most serious life-supporting environmental challenges. Annual economic losses caused directly by aridityrelated disasters have been more than 10 billion RMB since the beginning of 1990s, which greatly restricts the application of development strategies of national economy. Under the guidance of Global Change Science, a National Key Basic Research Science Foundation（973 project）“Evolution of Life-supporting Environment in Our Nation and the Predictive Study of Aridification in Northern China” has carried out integrated studies on the living environment consisted of various components, such as water, soil, air, and life, etc. Aimed to put forward scientific bases for the evolution prediction, impact assessments and adaptation measures of aridification, the project revealed the mechanisms of the formation of aridification from the viewpoint of the comprehensive changes in monsoon environmental system. Notable results have been achieved since the application of the project over the past 5 years both in the fields of social demand meeting and scientific creativities. The main scientific issues and achievements of this project are introduced in this paper.