Supported by the National Science Foundation（NSF）, the Long-Term Ecological Research Program was launched in 1980. Since then, it has achieved great success in creating theories, developing integrated technologies and providing services to society. Its process can be divided into three phases, each of which takes about 10 years. In the first phase, the first priorities were site-based studies of the five core areas dealing with process and pattern of ecosystems and data collection and archiving. The second phase started from 1990 and researche focused on the cross-site studies and the impacts of human activities on ecosystems in larger scale. During the third  phase starting from 21st century, research will be proposed to concentrate on synthesis, ecological prediction and better services to society. Meanwhile, biodiversity study and informatics development should be added to the core functions of the program.