Lake Dood is a fresh water lake, remnant of a large glacial lake in the Darkhad basin.Northern Mongolia is located at the coordinate of 51°20′ N, 99°23′E, in 1538 m a.s.l..The length of the lake is 7.5 km with mean width 2.4 km (maximum width is 5.6 km).Mean depth of the lake Dood is 4.7 m, but deepest point is 17 m.The total area is about 41.3 km2.The climate of the Darkhad Basin is extremely continental with a mean annual temperature range of 40℃ and a mean annual precipitation of 300~400 mm.Thus, the lake Dood occupies a transition zone between mountain and forest steppe ecosystems to the south and the coniferous forests to the north.Because of its unique geographic location, this region is very sensitive to climate changes and ideal place for paleoclimate investigation.This paper makes an attempt to reconstruct the paleoclimate changes in Early Holocene and Late Pleistocene based on results of isotope geochemistry analysis of the core 1, obtained from the Lake Dood in North Mongolia, during the Mongolian-Russian joint expedition in summer of 2005.