There is provided a novel use of ramalin for preventing or treating liver diseases, and more specifically, a pharmaceutical composition for preventing or treating hepatic fibrosis or cirrhosis containing ramalin or a pharmaceutically acceptable salt thereof, and a functional food containing the same. It was confirmed that at the time of applying ramalin, which is a compound derived from Ramalina terebrata according to the present invention, to animal models, ramalin may remarkably suppress hepatic fibrosis and lower liver cirrhosis levels as compared to silymarin known as a liver cell protecting ingredient without cytotoxicity to normal liver cells, such that ramalin may be effectively used for preventing or treating hepatic fibrosis and liver cirrhosis.