Abstract: The grain size characteristics of sediments are important indicators for studying the substances transport in the coastal zone. To understand the grain size characteristics and dynamic environment of the sediments on the beaches of Leizhou Peninsula, 40 sediment samples were collected from four beaches, including Donghai Island in the east, Wuyang in the northeast, Nanji Village in the south, and Wushi in the west, and their grain size characteristics were analyzed. The relationships between the grain size of the sediments on the beaches of Leizhou Peninsula and factors such as topography and morphology, sedimentary dynamics, and human activities were explored. The results show that the sediment types in the study area are mainly sand, with only a small amount of clay and silt compositions in some areas. The mean grain size of the beach sediments in the study area, from coarse to fine, is Nanji Village ＞ Donghai Island ＞ Wushi ＞ Wuyang. The sorting is good and relatively good, the skewness is nearly symmetrical, and the kurtosis is moderate. The typical frequency curve of the sediments in the study area is unimodal, and the probability cumulative curve is one-stage. The main sources of beach sediments are coastal erosion and sands transported from the continental shelf. The coastal current and waves are the main driving forces for beach sedimentation, and the impact of sea level change is continuous and gradual. The influence of human activities is increasingly significant.