Abstract: Based on the remote sensing and measured data, we studied the suspended sediment distribution off Guangli and the influence of sediment diffusion from the Yellow River estuary. The results show that: (1) in a fair weather condition, the sediment concentration is less than 0.1 kg/m³ in the study area, and the straight distance of sediment diffusion from the Yellow River estuary to the south is only 10~20 km. In the strong wind condition, however, sediment concentration rises to 0.5 kg/m³ or above, and the diffusion distance to the south reaches 30~40 km that brings certain influence to the study area; (2) based on the sediment concentration, sediment grain size and silting / scouring characteristics of the Guangli harbor waters, it is revealed that the sediment diffusion from the Yellow River estuary is limited. The main sediment sources which caused deposition in the waterway or the basin are those transported by the joint action of wind waves and tidal currents; (3) since the sediment from the Yellow River estuary is in a trend of decrease, the influence of the sediment diffusion of the Yellow River is getting smaller.