Thermal diffusivity is a physical quantity that represents the thermal properties of soil. Amid the climate change known as global warming faced by humanity, Antarctica is one of the regions most affected by such changes. Therefore, in order to counter the effects of climate change, the thermal diffusivity of Antarctic regions is estimated in advance. In this study, the thermal diffusivities of four different locations near the King Sejong Station were estimated using temperature data measured in Antarctic soils, and temperature time series data were simulated using the finite element method. The thermal dynamic of active layer is analyzed in the soil temperature with high temporal resolution and high accuracy. In active layer of Antarctica area, calculation of thermal diffusivity is closely correlated with the freezing of excess water. From the warm and cold period, the pattern of heat production was calculated at the depth of 20 cm. The results showed that the thermal diffusivities of SJL1, SJL2 and SJL4 were 14 × 10^-7, 12 × 10^-7, and 11 × 10^-7 m²/s with root-mean-square (RMS) errors of 0.19953, 0.21182, and 0.32168°C, respectively. The shallow geothermal gradient data of study points showed the change from cooling and heating processes except SJL3 point. The calculated thermal diffusivities of the study points range from 11~14 × 10^-7 m²/s, which is consistent with previous reports.