Instrumental neutron activation analysis and ICP-OES were used to determine 3 8 elements in two lichen species namely Xanthoria parietina (L.) Th. Fr. and Parmelia tiliacea (Hoffm) Ach. which were collected in Aegean Region of Turkey. It was found that the accumulation capacities of two species differed only for the elements Ca, Cl, Cu and Pb by using ANOVA at 95% confidence level. Average concentrations of all elements except for Ba, Mn and Hg were higher in Parmelia tiliacea. For the elements Ba, Br, Co, Cr, Cs, Fe, K, Mg, Mn, Mo, Rb, Sb and Ti, the equation y - ax+b could be used to make interchangeability possible between two species.