Dating and grain-size analysis were conducted for the two cores taken at station 16 and 31 in the coastal mud area of the East China Sea. The results show that the mean sedimentation rate is 3.27 cm/a for the core 16 during the period of 1954~2003 and 0.8 cm/a for the core 31 during the period of 1822~2003. Based on grain-size characters, it is inferred that the sediments of the core 16 is influenced by the shifting of the trunk stream of the Yangtze River and the variation of sediment discharge. And the sediments of core 31 is controlled by the East Asian Monsoon since 1900 A.D. The sedimentary records of storm tide and flood are fit well with the history records, that provides a basis for geohazard study.