通过对长兴、横沙两岛潮滩沉积物粒度概率曲线的分析，揭示了潮滩沉积 物的以下特点：１．以跃移组分为主，悬移组分次之，滚动组分极少；２．随着沉积物 的变细，跃移组分含量呈减少趋势，悬移组分相反；３．跃移和悬移组分具有显著的 双段式特征，反映了潮流的双向搬运和沉积作用；４．跃移－悬移组分的临界粒径 （）与样品的平均粒径Ｍ（）之间呈抛物线型正相关。 By analyzing the particle size probability curves of tidal flat sediments in Changxing and Hengsha, the following characteristics of tidal flat sediments are revealed: 1. In order to jump the main component, followed by suspended components, rolling components rarely; 2. With the sediment thinning, the content of the transitional component shows a decreasing tendency, and the opposite of the suspended component.3. The transitional and suspended components have significant two-stage characteristics, which reflect the bidirectional handling and sedimentation of the tidal current.4. The critical particle size of the transition-suspension component () is parabolic positively correlated with the average particle size M () of the sample.