Abstract: This study examined 121 sets of surface sediments collected from Qinzhou Bay, Guangxi, China, determining their grain sizes and macroelement contents and analyzing the characteristics, spatial distribution patterns, and sources of microelement assemblages. The results indicate the presence of eight types of surface sediments in Qinzhou Bay, which are dominated by sands and silty sands in terms of grain size. The surface sediments featured a stable macroelement composition, with SiO₂, Al₂O₃, Fe₂O₃, and CaO accounting for about 95.54% of the total sediments. Of these, SiO₂ and Al₂O₃ exhibited the highest contents, averaging 73.23% and 8.71%, respectively. Compared to the upper continental crust (UCC), these surface sediments are enriched in SiO₂, MnO, and TiO₂ but depleted in other elements. These sediments displayed similar spatial distribution patterns of Al₂O₃, MgO, TiO₂, K₂O, and Na₂O. The significant positive correlations between these oxides indicate similar factors governing their distributions. Using Al as a reference, the enrichment factors (EFs) of nine macroelements in the study area were calculated. The results indicate that these elements largely originated from the UCC, with those from some sites being potentially affected by other factors. A comprehensive analysis of correlation and R factors shows that the ten types of macroelements in the study area can be divided into three categories. The first category consists of SiO₂, Al₂O₃, Fe₂O₃, MgO, MnO, TiO₂, K₂O, and Na₂O, suggesting a source of terrigenous clastic sediments. The second category is CaO, principally representinga marine biological source. The third type comprises P₂O₅, representinga mariculture source. The analysis of these sediment sources using the PCA-MLR model reveals that the three sources exhibit relative contribution rates of 46.14%, 15%, and 38.86%, respectively.