Total organic carbon (TOC) in lake sediments depends on the input of organic matter, the primary production of lake itself and its preservation potency while the stable isotope value (δ¹³C) of organic carbon reflects the combination of different sources of organic matter and the paleovegetation in the drainage area-According to the vertical distribution of TOC and δ¹³C, combined with the sedimentary characteristics, sporo-pollen and diatom from Dongiutian coalfild of Hulun Lake, Inner Mongolia, the paleoenvironmental evolution of this region since last Glaciation has been reconstructed as follows: the lake pioneering period of LGM or a bit later, cold and dry;the highest lake level period of the second half of Post Glacial (13000-10900 a B.P.), temperate and wet;Younger Dryas Period(10900-10600a B.P.), cold and dry;the higher lake level period at the beginning of Holocene (10600-10000a B.P.), temperate and wet;the in ter mediate-low lake level in the Early Holocene (10000-7200a B.P.), temperate and dry;the higher lake level of Middle Holocene (7200-5000a B.P.), warm and wet;the strong shrinkage period in the late Middle Holocene (5000-3000a B.P.), temperate and dry.