Xingkai Lake is situated at mid-high latitudes,where the climate is dry and cold in winter due to the regime of the Mongolia High;in summer,however,the climate is rainy and hot owing to the heat-and-moisture-abundant maritime air masses.Located on the border of China and Russia,the lake is the largest freshwater body in NE Asia and has been listed as one of the most important sites for global lake drilling in the pole-equator-pole(PEP) belts project within the context of past global changes(PAGES) project.In our work,lake drilling was first carried out in Xingkai Lake and two 270 cm long parallel sedimentary cores were acquired successfully.Paleoclimatic and paleoenvironmental changes of Xingkai Lake since the 28 ka BP was revealed,based on down-core analysis of pollen,grain size,total organic carbon(TOC) and total nitrogen(TN),organic δ~(13)C_(org) and δ~(15)N_(org),diffuse reflectance spectroscopy(redness and brightness) and susceptibility and the synthesis of the above multi-proxy analysis.It is revealed that high percentages of coarse silt and sand reflected low stands of the lake water as a result of decreased rainfall,increases in fine silt indicated high lake levels due to increased rainfall and high contents of clay reflected lentic sedimentary environment under dry conditions.Averaging at 11.4,the C/N ratios show positive correlations with the TOC values,indicating the organic matters of the lake sediment originated mainly from the watershed of the lake,i.e.from the riverine materials.The negative correlations between the values of TOC andδ~(15)N_(org) also indicate that the organic matters in sediment came mainly from the advanced vegetation in the catchment.Hence,low δ~(15)N_(org),values and high TOC values indicate warm and humid climate while high δ~(15)N_(org) values and low TOC values indicate cold and dry climate under which the organic matters of the lake came mainly from lacustrine planktonics(of course decreases in nutrients input to the lake could have also resulted in reductions in δ~(15)N_(org) values).In addition,warm and humid climate was also indicated by the high values of redness and low values of brightness,while cold and dry climate was also reflected by the low values of susceptibility and coarse grain sizes. Xingkai Lake is situated at mid-high latitudes, where the climate is dry and cold in winter due to the regime of the Mongolia High; in summer, however, the climate is rainy and hot owing to the heat-and-moisture-abundant maritime air masses. Located on the border of China and Russia, the lake is the largest freshwater body in NE Asia and has been listed as one of the most important sites for global lake drilling in the pole-equator-pole (PEP) belts project within the context of past global changes (PAGES) project. In our work, lake drilling was first carried out in Xingkai Lake and two 270 cm long parallel sedimentary cores were acquired successfully. PALEoclimatic and paleoenvironmental changes of Xingkai Lake since the 28 ka BP was revealed , based on down-core analysis of pollen, grain size, total organic carbon (TOC) and total nitrogen (TN), organic δ ~ (13) C org and δ ~ (15) N org diffuse reflectance spectroscopy (redness and brightness) and susceptibility and the synthesis of the above multi-proxy analysis. It is revealed that high percentages of coarse silt and sand reflected low stands of lake water as a result of decreased rainfall, increases in fine silt indicated high lake levels due to increasing rainfall and high contents of clay reflected lentic sedimentary environment under dry Averages at 11.4, the C / N ratios show positive correlations with the TOC values, indicating the organic matters of the lake sediment originated mainly from the watershed of the lake, iefrom the riverine materials. The negative correlations between the values ​​of TOC and δ ~ (15) N_ (org) also indicate that organic matters in sediment came mainly from the advanced vegetation in the catchment .ence, low δ ~ (15) N_ (org), values ​​and high TOC values ​​indicate warm and humid climate while high δ ~ (15) N ~ (org) values ​​and low TOC values ​​indicate cold and dry climate under which the organic matters of the lake came mainly from lacustrine planktonics (of course decreases in nutrients input to the lake could have also resulted in reductions in δ ~ (15) N_ (org) values) .In addition, warm and humid climate was also indicated by the high values ​​of redness and low values ​​of brightness, while cold and dry climate was also reflected by the low values ​​of susceptibility and coarse grain sizes.