Abstract: Concentrated upon the data of samples of suspended matter and surface sediment in the Xiaoqing River estuary collected in January 2007,concentration and grain size of the suspended matters vary strongly in the horizontal and vertical directions, but they both have the orderliness in the spatial distribution and are basically controlled by the ocean dynamic process. The concentration of suspended matters in different depths of water increases seaward from 50~80 mg/L to more than 100 mg/L, and the east region of mouth bar of the Xiaoqing River with higher concentration of 90~100 mg/L extends to the northeast part of the investigated area with increased concentration. The vertical distribution of the suspended matter is steady in the river mouth but stratified in the water course and south region of lower concentration. The results of comparing the grain size of the suspended matters with that of the surface sediment reveal they have an af-finity, while the grain size changed with the same direction as its concentration. Integrated the published conclusions into this study explains that most of the suspended matters in the Xiaoqing River are those taken from the river and the tidal beach along the riverbed, while the main factors influencing the charac-teristics of suspended matter in water of Xiaoqing River estuary are the resuspended action of the surface sediment and the transportation from the beach.