Presented at the 2014 Ocean Sciences MeetingPacific salinity variations in the North Hemisphere Ocean are examined by using Ishii v6.9 datasets from 1980 through 2010. It obviously reveals that salinity varies geographically and time. Two key regions, the 15°N to 30°N latitude band and the Southeast Pacific subtropical zone, show large salinity values. With the depth deepening, these two regions extend southwest and west respectively but the salinity values decrease. Till 250m, there is an equatorward displacement of more than 6 degrees of the north key region, while the south one moves west of 40 degrees. On the context of global warming, salinity of the Kuroshio extension region keeps showing decreasing tendency regardless of the depth. There are two other significant decreasing regions resembling tube-like. One's threshold begins at the surface of California Current region to the 500m layer of the KE region in southwest-northeast direction while the other one begins at the Southeast Pacific upwelling region to the 500m layer of the warm pool. Salinity spatial distribution also shows significant low-frequency variations relative to large-scale climate factors. Subsurface freshening associated with the NPGO during 1998 and 2003 of he Northeast Pacific and the remarkable difference between surface and 10m depth salinity during 1997/98 El Niño event are explained and studied.