Time-series data from subsurface moorings, U5 and UB2, and vertical profile data of conductivity-temperature-depth (CTD) were collected in the southwestern East Sea (Japan Sea). The moored current-meter data were collected using rotary-current meters (RCMs) at U5 at depths of 1000 and 2000 m from November 2002 to May 2006 and at UB2 at depths of 1000 and 1600 m from May 2006 to February 2010. Sampling intervals of the RCMs were 30 minutes or an hour. Six vertical profiles of temperature and salinity were collected using standard CTD instruments near U5 in August 1995, March 1997, June 1999, September 2005, August 2008, and October 2012. The data were quality controlled and quality assured before provision to the community via SEANOE.