Listvyanka monitoring station is located in a rural area at the shore of Lake Baikal,Irkutsk Region(Russia).Long-term air mercury monitoring at the station within GMOS(Global Mercury Observation System)started in October 2011.Measurements were taken with Lumex RA-915AM air mercury monitor,which provides continuous background mercury monitoring in compliance with EN 15852 standard.The long-term monitoring shows obvious seasonal variation of the background mercury concentration in air,increasing in winter season with a monthly average maxima of 1.60-1.8 ng/m3 in January,and decreasing in summer with a monthly average minima of 1.1 – 1.2 ng/m3 in August-September.The overall average concentration at Listvyanka site from Oct 2011 to May 2014 is 1.42 ng/m3 with the annual average of 1,45 in 2012 and 1.35 ng/m3 in 2013,respectively(in Irkutsk region,year 2012 was colder as compared to 2013).Local short-term concentration rises are associated mainly with NNW wind carrying air from industrial areas of Irkutsk and Angarsk cities(70 and 100 km away from Listvyanka)where five big coal-fired power plants are located.These power plants are main sources of short-term Hg concentrations rises.A positive correlation between mercury and SO2 concentrations is observed both in the short-term variations and monthly average concentrations.