Abstract: Effect of sediment deposition on germination and seedling growth of Potamogeton crispus was studied through an experiment. Results show that sediment deposition deferred its germination,but did not affect much its eventual germination rate; thickness of deposition did not affect the number of leaves of its seedlings but did affect the length,width and area of its leaves, which decreased, while the length/width ratio of its leaves increased with the increase in thickness of the deposition; and the biomass of P.crispus per plant decreased with the increase of thickness of the deposition.