Abstract: Geochemical characteristics and geological significance of surface sediments from the Qiongdongnan area are studied. 88 sediment samples have been analyzed for their major element contents. SiO₂ is of the highest content in the area, with its mean content up to 41.15%. CaO following SiO₂, its mean content is 15.66%.Terrestrial clasts in the area were mainly carried by Honghe River from Western Yunnan Plateau. Factor analysis shows that SiO₂,Al₂O₃,Fe₂O₃,MgO,K₂O and TiO₂ originate from terrestrial source and CaO,CaCO₃ and LOSS are mainly derived from marine calcicolous livings. Meanwhile, P₂O₅ and C_org mainly come from mixed terrestrial matrials and marine livings and Na₂O and MnO are mostly products of marine chemistry or volcanism. However, the components of terrestrial clastic and biological materials are primary factors that control the chemical compositions of sediments in the study area.