In the south-east of the Southern Yellow Sea., there is often a strong intrusion water with higher temperature and salinity originated from Tsushima Current. It is named at the present the Southern Yellow Sea Warm Current Water. Using the data from National Oceanographic Bureau of China and Fisheries Research and Development Agency of the Republic of Korea for years 1976-1979, the authors obtained the average December temperature-salinity of the body of the Southern Yellow Sea Warm Current Water, its seasonal changes, and its year by year variance. The results of its T-S Diagram analysis are presented.