Abstract: Grain size analysis for winter and summer sediments collected from the abandoned Yellow River delta of northern Jiangsu was made for study of the spatial and temporal distribution of grain-size parameters in different seasons. Results show that sediment particle size becomes coarsen form coast to offshore and form north to south in the study area spatially, and is coarser in winter than in summer temporally. Generally, the sediment is poorly sorted, with a positive skewness and sharp kurtosis. Since the effect of wind is different in seasons, the grain-size parameters are more complex in winter times, and all the parameters vary in a broad range. Laterally, the gradients of grain-size parameters for the samples collected in winter times are obviously larger than those from summer samples. The sediment with a peak value around 52.55~88.39 μm was identified as a sensitive size to climatic change. Due to the joint action of wave and tide under the driving of monsoon, the study area is characterized by complex dynamics.