Abstract: The change of beach topography is the result of complex topographic dynamic process with many information of temporal and spatial characters. In this paper, the empirical orthogonal function (EOF) was used to analyze beach profile data of Puqian Bay, Haikou Bay and Chengmai Bay in the southern coast of Qiongzhou Strait from April 2018 to March 2019. Results show that first, the first three spatial and temporal functions could represent the main modes for the changes of beach on the southern coast of Qiongzhou Strait. The first mode represented the beach accretion. Beaches of Puqian Bay and Haikou Bay showed the seasonal characteristics of silting from summer to autumn and eroding from winter to spring. Chengmai Bays beach had the seasonal characteristics of eroding in summer and autumn and silting in winter and spring. The second and third modes might be caused by the migration of the sediments on the beach influenced by storms, tidal levels, or by changes of the wave height and the tidal level, which were related to bay area topography, incident wave direction, sediment source, tidal range, wave height, storm path, etc. Second, artificial islands in Puqian Bay and Haikou Bay had increased the bays sheltering and promoted the silting of partial gulfs beaches. It takes times before the beach reached a new balance. Third, as a secondary control factor during the observation typhoon impacts on the beaches were found limited. At the same time, the beach response to typhoons was closely related to typhoon intensity, landing distance, relative typhoon position and degree of local terrain shelter.