The kinetics of Pb adsorption in seawater by surface sediments from Xiamen Bay was simulated and the effects of seawater conditions were studied . When water temperature changed from 20 to 30℃, pH from 5 to 8 and salinity from 30 to 4 . the adsorption rate increased by about 50% , one order of magnitude and 5 times, respectively . A negative exponential relation between the adsorption rate and salinity has been found . The adsorption processes can be simulated by the exchange- equilibrium kinetic model . Adsorption rate constant, apparent activation energy and equilibrium adsorptive capacity have been quantitatively determined . The adsorption of Pb by sediments is essentially a chemical action . The kinetics of Pb adsorption in seawater by surface sediments from Xiamen Bay was simulated and the effects of seawater conditions were studied. When water temperature changed from 20 to 30 ° C, the pH was from 5 to 8 and salinity from 30 to 4. The adsorption rate increased by about 50%, one order of magnitude and 5 times, respectively. A negative exponential relation between the adsorption rate and salinity has been found. The adsorption processes can be simulated by the exchange- equilibrium kinetic model. Adsorption rate constant, apparent activation energy and equilibrium adsorptive capacity have been quantitatively determined. The adsorption of Pb by sediments is essentially a chemical action.