During the wintertime monsoon, a double tongue-shaped thermohaline front is established at the Yellow Sea (YS) entrance where the warm and saline Cheju Warm Current water (CWCW), originating in the Kuroshio, and the cold and fresh coastal water meet. The frontal circulation have been investigated by analyzing CTD data, float tracks, and current data. The CWCW advances westward in the eastern part of the YS entrance and extends northwestward as a warm tongue along the western flank of the YS Trough, whereas the Chinese coastal water spreads southeastward as a cold tongue on the CB. The eastern part of the front generally runs in an east-to-west direction along 34°N, showing a wavelike meander motion and isotherms, isohalines, and isopycnals decline downward toward the north. On the other hand, the western part of the front develops southeastward approximately along the 50 m isobath of the CB, not showing the wavelike structure.ater meet. The frontal circulation have been investigated by analyzing CTD data, float tracks, and current data. The CWCW advances westward in the eastern part of the YS entrance and extends northwestward as a warm tongue along the western flank of the YS Trough, whereas the Chinese coastal water spreads southeastward as a cold tongue on the CB. The eastern part of the front generally runs in an east-to-west direction along 34°N, showing a wavelike meander motion and isotherms, isohalines, and isopycnals decline downward toward the north. On the other hand, the western part of the front develops southeastward approximately along the 50 m isobath of the CB, not showing the wavelike structure.