The warm pool in the western tropical Pacific Ocean is one of the major heat sources causing strong atmospheric convection, driving the Walker circulation and Hadley cell, hence influencing the global and East Asian climate. Facing the requirement of climate prediction,  variations and climatic impacts of ocean circulation and the warm pool in the tropical Pacific Ocean, a project of the National Basic Research Program Structure,was approved by the Ministry of Science and Technology of China in July, 2011. Three key scientific issues that will be addressed in the project are as follows.① Multi-scale interactions of oceanic dynamic processes associated with the formation and maintenance of the warm pool;② Roles of oceanic processes in warm pool′s thermohaline structure and its variations; ③ Influence of the warm pool variations on different types of El Nino and the East Asia Monsoon modulation. Focusing on the above key issues centered at the warm pool′s variations and climatic impacts, three aspects of investigations will be conducted under the project: ① Structures and variations of ocean circulation and warm pool in the tropical Pacific Ocean; ② Key processes and mechanisms of ocean circulation-warm pool interactions; ③Ocean-atmosphere interactions associated with the warm pool variations and their climatic impacts. In this project, we will try to identify and understand the processes, mechanisms and sensitive areas of the warm pool variations influencing the East Asian Monsoon and climate variations in China, and offer scientific and methodological bases for improving the capacity of the short term climate prediction by developing ocean model′s mixing parameterization and assimilation schemes of coupled model for the ENSO prediction.