Abstract: In-situ water temperature data collected during different seasons in 2010 and 2012 was compared with HYCOM reanalysis data. The results illustrated that temperature data derived from HYCOM is applicable in the Yellow Sea. Based on the HYCOM datasets, temporal and spatial variability of the thermal front and mixing front in the Yellow Sea was analyzed in detail. The results showed that the thermal front appeared in fall, became strongest in winter and disappeared gradually in spring. Seasonal variability of mixing front in the Yellow Sea was related to monsoon. Mixing front appeared in the fall and well developed in the winter. Suspended sediment was concentrated in onshore side of the thermal front that constrained the offshore transport. The thermal front in Chengshantou coastal area corresponded to mud deposit in shape and location, as the depo-center (40 m thick) was located at the onshore side of the thermal front while on the offshore side the mud thickness decreased sharply. The results indicated difference between locations of the thermal front and mixing front, as the mixing front was located at the west of the thermal front where strong mixing was unfavorable for sediment accumulation. At the east side of mixing front, suspended sediment concentration was high with low turbulence, which favored rapid sediment accumulation corresponding to the mud depo-center. The spatial differences and interaction between the thermal front and mixing front might be the dynamic mechanism dominating the formation of omega ("Ω") -shaped mud deposits.