Mathematical-geological studies of trace elements in deep-sea sediments of the South China Sea have been made on the basis of the information developed from Q-factor analysis. The factors controlling the trace element distribution appear to be (ⅰ) sedimentary facies related to water depth and submarine volcanism, and (ⅱ) authigenous precipitation associated with chemical or biochemical process. The characteristics of migration and concentration of trace elements are described as follows: (ⅰ) The elements Ni, Cu and Co are probably related to the adsorption of autMgenous colloidal Mn-solids; (ⅱ) some elements, such as B, Cr, Zr and Ti are largely adsorbed on clay minerals; (ⅲ) both Sr and Ca are of biogeneous enrichment; (ⅳ) Ba intergrows with Cu, Pb and Ag, indicating that Ba results mainly from submarine volcanic activity and partly from biological process. Mathematical-geological studies of trace elements in deep-sea sediments of the South China Sea have been made on the basis of the information developed from Q-factor analysis. The factors controlling the trace element distribution appear to be (i) sedimentary facies related to water depth and submarine volcanism, and (ii) authigenous precipitation associated with chemical or biochemical process. The characteristics of migration and concentration of trace elements are described as follows: (i) The elements Ni, Cu and Co are probably related to the adsorption of (ii) some elements, such as B, Cr, Zr and Ti are substantially adsorbed on clay minerals; (iii) both Sr and Ca are bio-enrichment; (iv) Ba intergrows with Cu, Pb and Ag, indicating that Ba results mainly from submarine volcanic activity and partly from biological process.