In the present paper, vertical thermohaline structure and its relation to currents in the Southern Yellow Sea are addressed, based on the temperature and salinity observations with Neil Brown Mark-III CTD and the current measurments from the bouys deployed in November, 1983. The thermohaline structure，which were firstly found in 1983，can be classified into these categories: (1) step structure caused by double diffusion, (2) double halocline structure., (3) temperature-inversion structure. Both the secondary halocline layer ?and temperature inversion layer were located in the Yellow Sea Cold Water at about the same depth, which suggests the existance of the Yellow Sea Warm Current.It appears that the Yellow Sea Warm Current, as a compensation current, flows into the central Southern Yellow Sea from west of Cheju Island in the bottom layer.