In this study, the spatial distribution and seasonal changes of suspended particulate matter (SPM) concentrations near radial sand ridge areas off China’s Subei Coast are addressed, based upon field measurements conducted during spring and autumn. The results show that the SPM concentrations have higher values in spring than in autumn, and that higher concentrations of SPM occur in the near-bottom layer in both seasons; also, the nearshore areas have higher concentrations of SPM than offshore. In addition, a robust linear relationship was established between the SPM concentrations (mgL^-1) and in situ remote sensing reflectance (Rrs) (R² = 0.944, n = 39), and then the concentrations of SPM are retrieved from the satellite images, which have a good corresponding relationship with in situ SPM concentrations. There are significant differences between SPM concentrations in spring and those in autumn. The SPM in the study area is mainly derived from the resuspension of the seabed sediments in the radial sand ridges (abandoned Huanghe-Changjiang River multiple delta).