Abstract: The South China Sea is located at the western edge of the Pacific Ocean. The local thermal and dynamic structure of the rainy season combined with the movement of the subtropical high makes the convection in this area very active. The South China Sea is not far from the mainland, and the interaction between sea and land (thermal circulation, aerosol concentration) may have huge impact on the formation of precipitation in this area. Raindrop spectrum is the most basic physical quantity to study the microphysical characteristics of precipitation. It is important to analyze the characteristics of raindrop spectrum to deepen the understanding of cloud precipitation microphysical processes, improve the accuracy of radar inversion precipitation, improve the prediction of numerical models, and study the distribution of global water resources. This paper analyzed the raindrop spectrum data of Yongxing Island, Coral Island, and Sanya City from July 2018 to June 2019. The characteristics of raindrop diameter and Gamma parameter distribution were analyzed, which is helpful for understanding the precipitation microphysics mechanism in the South China Sea.