Abstract: Many scientific researches have been done on different faunal assemblages in relation to the environmentalcondition from thermal sources located on the eastern Aegean Sea coast. Aliağa (İzmir) region has also thermalresources. These two thermal springs are closely located on the coast of Ilıca Cape, northwest of Aliağa (İzmir) andnorthwest of Karaağaç Cove. Their temperatures are 40°C and 51°C, respectively. The bottom deposits consist ofrock fragments, gravel, sand, silt and clay units in the study area.In this research, 13 bottom sediment samples taken from different points and corresponding depths in the sea betweenthe Ilıca Cape and the Taşlı Cape were examined. Heavy metal analysis in the sediment samples were done by usingICP-MS. In addition, the results of trace element analysis and total Alpha and Beta features in the samples takenfrom the sea surface and spring waters were evaluated. The aim is to interpret meiobenthic living conditions byinvestigating on the effect of thermal springs the benthic foraminifera, ostracod and mollusk assemblages in thisregion.It was observed that the typical Aegean Sea foraminifera fauna composed of 32 genera and 50 species predominatedin the studied samples. An important peculiarity of the region is absence of amphistegina lobifera and peneroplidgenera and species commonly observed in the Aegean coasts of Turkey. Widely known nineteen genera and twentyeight species from Ostracods were found in Mediterranean and Aegean Sea. Mollusc faunas consist of 9 genera and10 species from gastropods, 14 genera and 14 species from bivalves.The other an important finding in the deposits are the presence of numerous gypsum crystals in sample A11. Thisfinding is an indication of an old thermal source. Furthermore, distribution of zinc (Zn), lead (Pb), Cooper (Cu) andarsenic (As) as the heavy metals in the same sample were found to be the highest. In these examples, a few speciesof foraminifera and only one species from ostracods and bivalves were found.