Based on the data of the sea fog field observation experiments in the east coast of Donghai Island in Zhanjiang City,Guangdong Province,China in 2010 and 2011,this paper made the comprehensive analysis on the macro-microphysical characteristics of fogs,properties of aerosols and fog water chemical compositions in the sea fog cases,and further discussed the mechanisms of sea fog formation and growth.Results show that the annual average sea fog days are 20—30 d.The most sea fogs are affected by depression system or cold front.The average liquid water content(LWC) of fog droplets are 0.019 and 0.072 g·m^-3 in 2010 and 2011,respectively.Low LWC is due to the accelerated turbulence deposition of fog droplets in the border of land-sea.The ratio of number concentrations between fog droplets and aerosols increases with the growth of LWC.The main ions in the fog water are Na⁺and Cl^-,and the two-year average values of total ion concentration(TIC) of Na⁺and Cl^-are 38 260 and 5 600 μeq·L^-1,respectively,but the ion loadings are almost in the same magnitude.The decline of TIC may be mainly owing to the growth of LWC in 2011.Activation and condensation growth play an important role on the formation and growth of sea fog droplets.Compared with continent and mountain fogs,the influences of coagulation,turbulence and advection factors are more significant in the sea fog cases.The spectra of fog droplets can be expressed by formula of Gamma and the spectra width broadens by the strength of coagulation.