Abstract: Four groups of numerical experiments covering two heavy sea fog events (March 6-8, 2006 and March 27-28, 2012) over the Yellow Sea were conducted by using WRF model and its 3DVAR system. The simulation results showed that the simulated fog areas were very similar to the observation for the dense sea fog case in 2006 if YSU was adopted as boundary layer scheme and Lin was chosen as cloud microphysical scheme. The simulated fog areas of YSU and Thompson scheme, MYNN and Lin scheme came second. When adopting MYJ as boundary layer scheme, the simulated fog areas were very poor compared with observation regardless of the cloud microphysical scheme. For the thin sea fog case in 2012, simulated sea fog area mostly depended on boundary layer scheme but little on cloud microphysical scheme. The best combination of boundary layer scheme was MYNN, while neither YUS nor MYJ can properly simulate the sea fog process.