Many large-scale land reclamation works are being performed along the south coast and the west coast in Korean Peninsula and left coast of Ishim River in Astana (Kazakhstan). A great amount soils are hydraulically filled by the dredging ship and various soil improvement techniques such as sand compaction piles on land and sea, plastic board drains, packed drains, horizontal and vertical vacuum consolidations, dynamic compaction, deep mixing method, progressive trenching method are being used for stabilization of soft ground. This paper describes soil improvement methods of the Incheon and Astana International Airports in Korea and Kazakhstan. The selection of soil improvement method is depended on geological formation of soil, soil characteristics, cost, availability of back-fill material, and experience in the past.