In this study, epiphytic lichen Xanthoria parietina was applied as the biomonitor of air pollution to determine the environmental influence in the vicinity of Soma coal-fired power plant. Thalli of lichen Xanthoria parietina growing on olive, oak and poplar trees were collected with their substrate in 2004-2006. They were taken from 44 different stations located in 3x3 km grids within an area of 30 km in diameter around the Soma power plant near the town of Soma. Lichen samples were analyzed by using the ICP-MS for As, Cd, Co, Cr, Cu, Fe, Hg, Ni, Pb, Se, Th, U, V and Zn elements and their concentrations were mapped. The sample analyses results were evaluated by using the statistical software (SPSS 11). Average element contents of samples were, in descending order, Fe > Zn > V > Pb > Cr > Cu > Ni > As > Co > U > Th > Se > Cd > Hg. Results obtained in the current study were generally found to be higher than the data reported in literature although some lower values exist for Cd, Co, Hg, Ni, Pb elements. The most polluted areas were found to be those in the vicinity of the coal-fired power plant, particularly along the direction of predominant wind and in the corridor which runs from west to southeast direction due to topographic conditions. We believe that this research which is conducted around a coal-fired power plant will shed light on future research on pollution.