Traditional Loran-C is used to the main radio navigation system, with the rapidly development of technology in recent years, enhance Loran-C begins to develop. The development of enhance Loran-C at home and aboard is firstly introduced in this paper, and then the definition of enhance Loran-C, enhance different Loran-C and miniaturization Loran-C transmitter form abroad are described in detail. Finally, enhance Loran C system is pointed out to be the important backup and supplement of GNSS, and to be the special role in the marine navigation.