The recent advances in the studies on the North Atlantic oscillation(NAO) are reviewed. Some long time series of NAO index are established using both the instrumental and proxy data. The instrumental series is now extended back to AD1825. Proxy NAO indices reconstructed using tree ring data and/or ice core now attract more attention. Multiple proxy reconstruction is now widely accepted for the purpose to reduce the uncertainty regarding of the individual proxy. As long as about three centuries’ proxy NAO indices provide good representation of variability in natural context. The impacts of NAO on the climate are now studied in more details and have been connected to Arctic oscillation (AO). NAO and AO are the two paradigms of one phenomenon. Some model studies confirm that the thermohaline circulation (THC) may plays very important role in the low frequency of NAO. Some other external forces such as ozone and greenhouse warming are also considered as potential contributor to the observed recent trends in NAO.