East Asia is the largest anthropogenic Hg emission source region globally. Therefore, increasing atmospheric mercury (Hg) measurements have been conducted in East Asia and its downwind regions, such as in China, Japan, Korea, Taiwan, and over the North Pacific Ocean. Nonetheless, speciated measurement data are still limited. Besides, atmospheric Hg data are very rare for the Southeast Asia, a region with many small-scale gold mining and intensive biomass burning activities that could contribute significant amount of Hg to the atmosphere. Systematic monitoring of Hg in the atmosphere and rainwater in Taiwan has been started since 2006. Speciated atmospheric Hg has been measured since April 13, 2006 at the Lulin Atmospheric Background Station (LABS; 120.87ºE, 23.47ºN, 2862 m a.s.l.) in central Taiwan to collect baseline information of Hg in the free troposphere and to study the trans-boundary transport of Hg from regional and global sources. A nation-wide wet Hg deposition monitoring network, consisting of 11 sampling sites in Taiwan and a remote islet site in subtropical Northwest Pacific Ocean, was established to collect weekly rainwater samples for Hg analysis since late 2008. The purpose of this network is to establish a national database of Hg concentration in precipitation and the associated wet deposition fluxes. Since 2010, our group has collaborated with local scientists via the 7-SEAS research project to study the distribution of atmospheric Hg in northern Thailand and Vietnam during the spring biomass burning season. In 2012, USEPA, Taiwan EPA, NADP, Environment Canada and the National Central University in Taiwan with partners in Southeast Asia launched the Asia Pacific Mercury Monitoring Network (APMMN) for tracking the atmospheric transport and deposition of Hg in the Asia-Pacific region. The initial phase of the APMMN is a cooperative pilot Hg wet deposition monitoring network in Southeast Asia (Thailand, Indonesia, and Vietnam), with technical support from several organizations in Taiwan, Japan, South Korea and the United States. Monitoring will begin in September 2014 and the pilot network will operate for three years