© The authors and ICE Publishing: All rights reserved, 2015.Liquefaction of sandy soils remains to have great importance for the geotechnical and civil engineering community as its economical and social consequences are usually weighty. Case histories revealed that various failures occurred due to static or flow- Type liquefaction including submarine slopes, mine tailings, spoil heaps, highway embankments and earth dams. And interestingly, in most cases the predominant soil type is sands with certain amount of silts rather than being clean. Today, it is well accepted that undrained behavior of clean sands and silty sands are not necessarily same in terms of liquefaction potential. However, the influence of silt on liquefaction mechanism is still debated. In this study, an experimental program is performed on a base sand, named as Sile Sand 80/100, mixed with three different non plastic silts: TT Silt, IZ Silt and SI Silt. Strain controlled undrained triaxial compression tests are conducted on resulting silty sands with 5%, 15% and 25% fines contents for each silt type. The influence of different silt characteristics such as gradation, mean size and shape effects on liquefaction potential of sand is discussed.