The expansive soils can be founded in various regions and extent areas in the south, middle and north of Iraq. Damage to these soils may appear immediately after construction within five years, or it may take several years until something happen to disturb to moisture structure of the soil. This work aims to find the relation between Atterberg limits, swelling potential, and swelling pressure for five samples. This work is projected to forecast the volume changes in site soil associated with the changes in soil plasticity. The behavior of an expansive soil (bentonite sand mixture) (B-S) subjected to the Atterberg limits test and swelling test were studied. Also, it was found that simple classification tests can provide reasonable estimates of field edges. The potential probability forecasts using the consolidation standard were sometimes low, often as little as possible compared to field observations. Predictions based on the soil suction method provided reasonable higher limits for all test sites.