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 detailed frontal structure and circulation have been investigated by analyzing comprehensive 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, but it is bounded by the shallow Changjiang Banks (CB) to the west. The Chinese coastal water spreads southeastward as a cold tongue on the CB.ater meet. The detailed frontal structure and circulation have been investigated by analyzing comprehensive 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, but it is bounded by the shallow Changjiang Banks (CB) to the west. The Chinese coastal water spreads southeastward as a cold tongue on the CB.