In this paper the list of Gilan province lichen is presented. Because, comprehensive study has not been done on the lichen flora of the province yet, the results of this study create a general understanding of the species diversity of lichens in the province. Since lichens are many uses for man, the study of an area lichen flora is very important; such studies generate basic information about lichen of areas too. Today, Lichens has used as "Bioindicators" in the world and has been used to estimate the natural environment and urban pollution. In addition to thousands of valuable material derived from lichens that are very important in the industry, the food industry, the pharmaceutical industry and Cosmetics, detergents industries. Moreover, the environmental benefits of lichens are numerous; For example, are the pioneer of ecosystems and with creation of new conditions (e.g., soil production), cause entering of single-celled organisms, plants and animals to the isolated environments; lichens by the protection of soil, are causing stability in natural ecosystems too. In this research 500 lichen samples were collected which were belong to 81 species. 11 species of the 81 species are new for lichen flora of Gilan province. The collected samples are preserving in the Research Institute of Forests and Rangelands, Central Herbarium of Iran now.