Availability of free water plays a most important role in soil-forming and developing processes in the maritime Antarctic. Source and generation of free water, freeze-thaw process, permafrost and active-layer dynamics, and material translocation induced by leaching are expatiated in the article. Meanwhile, various factors driving and limiting the above-mentioned processes are analyzed. And pedogenetic significance of these water-based processes within soils is discussed. It is pointed out that within soils activities induced by moisture availability could vary greatly due to site difference in a small distance, thus, to some extent, determining genesis and development of individual soils and distribution pattern of soils in this region.