Abstract: Using the fog droplet spectrum data from Xiang’an District in Xiamen City from 2019 to 2021, the authors investigated the statistical characteristics of the microphysical parameters and fog droplet spectrum of sea fog on the southern coast of Fujian Province. Based on the relations among the visibility and particle number concentration (N), liquid water content (L) of fog, and relative humidity, authors established various parameterization schemes and evaluated the fitting effects of each scheme. The results showed that the average N and L of sea fog were 47.5 cm⁻³ and 0.0763 g m⁻³ on the southern coast of Fujian Province, respectively. N and L increased significantly with the enhancement of fog level, while the mean diameter and effective diameter increased slowly. When visibility dropped below 100 m, the average N and L reached 115.42 cm⁻³ and 0.228 g m⁻³, respectively. Additionally, the N and L spectra exhibited double peaks. The main N peak was located at 4–6 μm (particle diameter), and the secondary peak was at 22–26 μm. L showed the opposite characteristic, exhibiting the main peak at 24–26 μm and the secondary peak at 4–6 μm. This showed that the N of fog was mainly controlled by small droplets, but particles with a size of 20–30 μm contributed more to L. Compared with other coastal regions, the average N on the southern coast of Fujian Province was smaller than that on the southern coast of China but larger than that on the eastern coast of China. Meanwhile, the average L was larger than that of the southern coast but smaller than that of the eastern coast of China. In comparison, N for the same fog level was smaller in inland urban and rural regions, but L was larger. Moreover, four visibility parameterization schemes were established using full samples and a segmented method. Test results indicated that the visibility subsection fitting scheme based on L×N was optimal, especially for visibility below 1 km.