This paper mentions to a research and development on a propeller for an airboat. The propeller is designed for an airboat with 5.18 m in length, 1.98 m in breadth and 0.17 m in draft. The airboat is developed for rescues works from storms, floods in rainy season with bad weather conditions and operation on multi-terrain. A special feature in the design of the airboat is using a hybrid propulsion system, water propeller and air fan. With the advantage of using two propellers, the airboat can run on multi-terrains such as on water surface, reed areas, swamps, on muddy surfaces. This study will present a design of a propeller for the airboat when it runs on water surface. The propeller is designed base on ship theory and CFD test. A propeller with four blades was made for the airboat.