The seasonal variability of the physical characteristics of aerosol particles at the King Sejong Station in the Antarctic Peninsula was investigated over the period of March 2009 to February 2015. Clear seasonal cycles of the total particle concentrations (CN) were observed. The monthly mean CN<sub>2.5</sub> concentrations of particles with a particle size lager than 2.5 nm were the highest during the austral summer with a mean of 1080.39 ± 595.05 cm<sup>−3</sup> and were the lowest during the austral winter with corresponding values of 197.26 ± 71.71 cm<sup>−3</sup>. A seasonal pattern of the cloud condensation nuclei (CCN) concentrations coincided with the CN concentrations, where the concentrations were minimum in the winter and maximum in the summer. We also estimated values of fit parameter <i>C</i> and <i>k</i> based on measured CCN spectra. The values of <i>C</i> varied from 6.35 cm<sup>−3</sup> to 837.24 cm<sup>−3</sup>, with a mean of 171.48 ± 62.00 cm<sup>−3</sup>. The values of <i>k</i> ranged between 0.07 and 2.19, with a mean of 0.41 ± 0.10. In particular, the <i>k</i> values during the austral summer were higher than those during the winter, indicating that aerosol particles are more sensitive to supersaturation ratio (SS) changes during the summer than they are during the winter. Furthermore, the effects of the origin and the pathway travelled by the air mass on the physical characteristics of aerosol particles were determined. The modal diameter of aerosol particles that originated from the South Pacific Ocean showed seasonal variations; 0.023 µm in the winter and 0.034 µm in the summer for the Aitken mode and 0.086 µm in the winter and 0.109 µm in the summer for the accumulation mode.