In this study, the liquefaction behavior silty sand mixtures and volumetric deformation properties were investigated. The study was implemented on samples of silt sand mixtures obtained during an excavation at Bayrakh, Izmir, Turkey. In order to investigate the liquefaction behavior of silty sand, undrained cyclic triaxial compression tests were carried out according to JGS 0542-2000, for 8 different fines contents (0, 5, 10, 20, 40, 60, 80, 100%). To determine the volumetric deformation properties, the water content change was measured by allowing drainage into a burette upon completion of a cyclic test. The liquefaction criteria was determined by using intergranular-interfme void ratios. A threshold fines content to serve as liquefaction criterion has also been determined. The volumetric deformation properties behavior were reviewed depending on the silt content.