Liquefaction is a term used to describe a phenomenon in which excess pressure of the pore water pressure leads to significant softening or weakening of soil deposits. Due to the fact that the city of Bushehr is peninsular and coastal, the groundwater level is located at very low depth and since the soil is badly grained and uniform, the probability of static fluidization under the load of monotonics Very high. So, in this research, soil samples with low density and completely saturated soil were tested by a three-axis machine under non-drainage conditions. In these experiments, liquefaction was investigated by changing the amount of fine-grained soil from 0 to 24% in a 25 kPa sweep, and the approximate range of fine grains for liquefaction was determined.