Abstract: In order to understand the geochemical characteristics in surface sediments from Sanya offshore area, the contents of 23 trace elements in surface sediments of 331 stations were determined. Multivariate statistical method was used for correlation and R-type factor analysis to explore the source, distribution characteristics and control factors of elements in the study area. The determination of trace elements show that the average values of Sr, Ba, Zr and Rb are higher than those of other elements; The contents of 15 elements such as Be, Cr, Co, Ni, Cu, Zn, Cd, Sb, Pb, U, Zr, Ba, Sc, V and Ga are close to those of stream sediments, surface soil and deep soil in Hainan Island. It is speculated that the sediments mainly come from Hainan Island. The spatial distribution of elements in the study area is complex. In the middle and east, the contents of most trace elements(15) represented by Li increase with the increase of offshore distances; The distribution characteristics of Cd, Sb, Zr, Ba, Rb, Sr, As and Hg are significantly different from other trace elements. The source and distribution of 15 elements such as Li are mainly controlled by the adsorption of terrigenous clay minerals, the source and distribution of Sr are mainly controlled by marine biogenic sedimentation, the source and distribution of Zr are mainly controlled by heavy minerals, the source and distribution of Ba and Rb are mainly controlled by the geological background of the study area, while the source and distribution of Cd and As are related to human activities.

Key words: surface sediments, trace element, geochemistry, control factors, Sanya offshore area