The studies of the new climate mode-North Pacific Gyre Oscillation (NPGO) were reviewed, focusing on the observation phenomenon and dynamic mechanisms. The spatial structure of NPGO mode was characterized by a dipole-like center of the sea surface height anomalies in the North Pacific.The NPGO represented an intensification of both the subpolar and subtropical gyres when in positive phase, and this intensification was driven by openocean wind stress curl anomalies and by variations in wind-driven coastal upwelling. The NPGO was the oceanic express of the mid-latitude atmospheric NPO. The tropical coupled dynamics were involved in forcing the NPGO fluctuations, suggesting that the coupling effect of atmosphere and ocean between tropical Pacific and mid-latitude Pacific was important to illustrate the dynamic mechanisms of NPGO. Meanwhile, future prospects were advanced as follows: the variations of spatial structure of climate modes in the North Pacific; the relationship and interaction between atmospheric mode and NPGO mode; the roles of NPGO in the ecological transition; the influence of NPGO to interdecadal climate variabilities in China. 