To investigate size distributions of suspended sediments, the field measurement using LISST (Laser In-Situ Scatter and Transmissometer) was conducted on a sandy beach. The time-series of suspended sediment concentration (SSC) of a grain size in the sand range (63 to 500 μm) had strong correlations with those of other sand grain sizes, and the same trend was observed for silt (3 to 28 μm). However, the time-series of SSC of sands had little correlations with those of silts. The comparison between the estimated and measured grain size distributions of suspended sediments suggested that the assumption that SSC is inversely proportional to the sediment fall velocity can be applied to estimation of SSC of various grain sizes. With the increase in median sediment diameter, the sorting coefficient decreased and the skewness increased.
