NPOCE (the Northwestern Pacific Ocean Circulation and Climate Experiment) program is a multi-national, multi-institutional program, designed to observe, simulate, and understand the dynamics of the NWP (Northwestern Pacific) ocean circulation and its role in low-frequency modulations of regional and global climate including the western Pacific warm pool variability, the ITF variability, ENSO, the East Asian Monsoon (EAM), and the NWP cyclones. The coordinated observational program and modeling analysis shall provide a more complete description of the structure and variability of the ocean circulation in the NWP, and help improve prediction of the climate drivers discussed above, and projection of local/regional ocean and climate conditions. NPOCE is endorsed by Climate Variability and Predictability (CLIVAR) as an international cooperative program. NPOCE contributes to CLIVAR objectives, particularly to the notion of ocean process, ocean enhanced, and ocean sustained observations. Together with synergetic on-going projects, it will inform many upcoming projects about what and where the focus should be in order to address important issues, including the role of western boundary currents (WBCs) in the ENSO discharge/recharge process, in warm pool evolution and the ITF dynamics, and in tropical-extratropical interactions.