Abstract
This study aims to appear isotropic compression characteristic, shearing characteristics and changes of suction in unsaturated cohesive soils by freezing and thawing under undrained conditions. The pore water pressure increases by freezing and thawing and the suction in soils decreases. In isotropic compression, changes of suction in subjected to freezing and thawing soils is greatly. The decrease in the suction is related to the pore formation of soil structure and the decrease in sheare strength.