Abstract:Altogether 15 metal elements concentration of 216 lake sediment samples from CC1 core in Chen Co, southern Tibet were measured. Distribution features of all the metal elements and their relationship with grain size parameters was studied. The results showed that all the 15 elements could be divided into three groups according to their distribution features, i.e., 12 elements of K, Na, Mg, Al, Ti, Ba, Cu, Zn,Fe, Pb, Cr and V present similar variation trend against depth;Ca and Sr had very similar variation trend while Mn was not similar with any other element. The correlation analysis between elements concentration and grain size parameters indicate that the variation of Ca, Ti and Pb were not influenced by grain size distribution;8 elements (K, Na, Al, Ba, Cu, Fe, Cr, V) show positive correlation with clay content (<4μm) of the sediment;Mg, Zn and Mn have positive correlation with silt content (4-63μm) while Sr had good correlation with sand content (>63μm). The grain size effects of most elements in this study were coherent with other studies of elements grain size effects in lake sediments and marine sediments. Compared with reconstructed environmental information for the past ca.1400 years from this core, it could be found that the distribution characteristics of elements show rather good correspondence with environmental conditions during different stages. Variations of most elements show influences from sources of materials that is intensity of weathering and erosion in the drainage. However, Ca concentration was not affected by grain size of lake sediments, and performs very good correlation with carbonate content and Sr/Ba of sediments, indicating that influence