The accumulated in situ hydrographic survey as well as the satellite observed sea surface temperature (SST) show consistent westward shifting of the Yellow Sea Warm Salty Tongue (YSWST) in winter. A 2-D thermal model is used to show the westward shifting of the YSWST due to cooling and advection. The MITgcm is applied to simulate the circulation in the Yellow and East China Seas. Under the northern monsoon wind in winter, the sea surface height (SSH) is adjusted to have a ridge in the channel and a trough in the 50--70 m iso-bath in the Yellow Sea. The barotropic transport of SSH and baroclinic transport of horizontal density gradient play the major role for the shifting of the YSWST, while the Ekman wind drift plays a minor role.