ABSTRACT: Biogeochemical methods have been widely used for prospects in the recent years. This study aimsto determine biogeochemical anomalities in Platanus orientalis and Phragmites australis plant speciesgrowing the Mezitli Stream. Li, B, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Cd, Sn, Cs, Baand Pb element content of leaves and twigs of P. orientalis and P.australis, soil and stream water samplestaken from 8 stations in Mezitli (Mersin) area were determined with inductively coupled plasma - massspectrometry (ICP-MS). The result of the statistical analyses show that P. orientalis plant species(ontwigs) can also be used as an indicator plant for B(n = 10, r = 0,76, % 99 reliability, P < 0,01), Cr (n =12, r = -0,67, % 95 reliability, P < 0,05), Sr (n = 9, r = 0,72, %95 99 reliability, P < 0,05) and Pb (n =11, r = 0,63, % 95 reliability, P < 0,05) for biogeochemical prospecting. At the same time; P. australisplant species (on twigs) can be also used as an indicator plant for Cu (n = 11, r = -0,66, % 95 reliability,P < 0,05), Cr (n = 11, r = 0,64, % 95 reliability, P < 0,05) and Li (n = 10, r = 0,77, % 99 reliability, P <0,01) for biogeochemical prospecting. Also the inter-element relationship between the P.orientalis and P.australis plant species which were determined as indicator plants and soil were investigated for Cr, B, Sr,Pb, Cu, Li elements