ABSTRACT:  This study aims to compare the permeability coefficients calculated based on the particle sizeanalyses peculiar to the soil samples of some districts at Meşelik and Tepebaşı residential areas inEskişehir. The study area covers 6 km2. In this study, the properties of units in alluvial deposit cut by 29boreholes previously drilled in the area were examined from borehole logs contained in the geological  reports. On the basis of the sieve analyses, particle size distribution curves were drawn. The parametersof D60, D50, D30, D20, D10, I0, U, Cc values were calculated by using these graphs. Porosity values werecalculated by using Gs, specific density and water content. Permeability coefficients were also calculatedfor the units having no water content values considering the intervals accepted by the literature.Dependently or independently on porosity values, permeability coefficients were individually calculated byusing the Hazen, Kozeny-Carman, Breyer, Slichter, Terzaghi, USBR and Alyamani-Sen formulas, for eachcore samples from different depths of the boreholes and then the most appropriate formula for differentdepths and units was determined. Variations of permeability coefficient for different grain sizes andporosities were studied. Based on the outcomes of this study, calculated permeability coefficients arealmost similar for uniform soil units, however, different for non-uniform units. It is inferred that usingabove-mentioned approaches for estimation of permeability coefficient for clay material is not suitable. Asa conclusion, estimation of permeability coefficient using Breyer, Slitcher, Terzaghi and Alyamani-Senapproaches are more suitable for non-uniform units while Hazen, Cozeny-Carman ve USBR areapplicable for uniform units.