Abstract: Observations for 25 hours during a spring and neap tide cycle were carried ut at five sites of the southwestern Laizhou Bay on June 2015, together with suspended sediment sampling. Temporal and spatial changes in suspended sediment concentration were studied. The method of flux mechanism analysis was then adopted to study the transport mechanism of the suspended matter and the influence factors of concentration changes. Results show that the concentration of suspended sediment in the southwestern area of Laizhou Bay has a decreasing tendency from north to south and an increasing trend from surface to bottom. The concentration of suspended matter near the bottom peaked in both the ebb and flood tides, which is several times as high as the normal. The sediment transport during a tide cycle is asymmetry, and the advection transport dominates the suspended matter. Facts suggest that hydrodynamics is the principal factor affecting the change in suspended sediment concentration. The suspended sediment concentration has a positive correlation with flow rate. However, the peak concentration is mostly delayed by 1-2 h.