Abstract:Global ecological security becomes increasingly important with the intensive human activities. The function of ecological security is influenced by human activities, and in return, the efficiency of human activities will also be affected by the patterns of regional ecological security. Since the 1990s, China has initiated the construction of key projects “Yangtze Three Gorges Dam”, “Qinghai-Tibet Railway”, “West-to-East Gas Pipeline”, “West-to-East Electricity Transmission” and “South-to-North Water Transfer”, etc. The interaction between these projects and regional ecological security has particularly attracted the attention of Chinese government. It is not only important for the regional environmental protection, but also of significance for the smoothly implementation of various projects aimed to develop an ecological rehabilitation system and to design a regional ecological security pattern. This paper made a systematic analysis on the types and characteristics of key project construction and their effects on the environment, and on the basis of this, brought forward the basic principles and methodology for ecological rehabilitation and security pattern design in this construction. It was considered that the following issues should be addressed in the implementation of a key project: 1) analysis and evaluation of current regional ecological environment, 2) evaluation of anthropogenic disturbances and their ecological risk, 3) regional ecological rehabilitation and security pattern design, 4) scenario analysis of environmental benefits of regional ecological security pattern, 5) re-optimization of regional ecological system framework, and 6)establishment of regional ecosystem management plan.