Abstract: The water-air amphibious vehicle, a kind of vehicle that can operate both in water and air, has been a hot topic of recent research for its potential wide application prospects in military and civil fields. To better understand the design requirements of this kind of water-air transmedia vehicles, the characteristics of vehicles in different media are introduced including the aircraft, the surface ship and the submersible. Then a brief analysis is made to compare these three kinds of vehicles and summarize the possible characteristics of water-air transmedia vehicles. According to the flight structure, the current water-air amphibious vehicles are divided into three categories:fixed-wing vehicle, rotorcraft and bionic vehicle and the typical prototypes of each category are reviewed. Finally, the key technologies and challenges are discussed.