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The Yellow Sea (YS) is a potentially important receptor for enhanced anthropogenic Hg emissions from East Asia. In the past decade, high quality Hg data related to this marine system has a significant increase. Here we review the available total Hg data and then develop the first Hg mass balance to obtain insights into the sources, sinks, pathways and processes regulating the Hg cycle in the YS. The result suggests that a total of 178.9 ± 36.8 kmol Hg is held in the water column with an input of 109.7 ± 17.2 kmol year and an output of 89.7 ± 14.5 kmol year. The input mainly comes from atmospheric deposition (56.2 kmol or 51.2 % of the input) and river discharge (25.0 kmol or 22.8 % of the input). The output is dominated by Hg(0) evasion from sea surface (37.2 kmol or 41.5 % of the output) and sedimentation (33.0 kmol or 36.8 % of the output). Although the result shows an increase of Hg in the water column (~11 ± 13 % annually), the high uncertainties of the estimate suggest that this result should be considered carefully. Future mass balance development would benefit from improving the understanding of following processes: tempo-spatial variations of atmospheric Hg deposition (especially the dry deposition), riverine Hg distribution and fate in the estuary, air/sea Hg(0) exchange and the controlling factors, and the waterborne Hg scavenging as well as sedimentation in the open ocean. [ABSTRACT FROM AUTHOR]