Mercury emissions from various anthropogenic sources were measured to develop the emission factors and to estimate the total emission from major anthropogenic sources in Korea. Sampling and analysis were carried out employing Ontario Hydro method and US EPA method 101A. Mercury emission in flue gas was mainly speciated into gaseous form, particle bound Hg was less. Most of Hg emitted from vehicles was speciated in elemental form due to the lack of strong oxidants. Wide rage of variation in mercury speciation and emission concentration were found, related to the variation in fuel/waste types, operating conditions, flue gas compositions, air pollution control devices (APCDs) types, source specific characteristics and so on. Hg removal efficiency of the existing APCDs in an average ranged 23% to 92%. Uncontrolled and controlled mercury emission factors for each source type were estimated. Emission factors obtained in this study are lower due to the application of highly efficient APCDs in the facilities and better environmental management practices. The annual Hg emission estimated from major anthropogenic sources for the Republic of Korea ranged from 6.5 to 20.2 tons, with average emission of 12.8 tons based on the most updated real measurements. Thermal power plants (26%), oil refining (25%), cement kilns (21%>) and incinerators (municipal, industrial, medical, sewage sludge) (20%) are major Hg emission sources. Other sources (crematory, pulp and paper manufacturing, non ferrous metal manufacturing, glass manufacturing contributed about 8% of the total emission. Due to lack of data for some sources, more measurements should be carried out in future.