Due to undesired mechanical characteristics, some forest soils cause problems in road construction. Several methods have been proposed for stabilizing these types of soils. In this paper, the impact of two polymer materials on unconfined compression strength of a forest soil is investigated. The unconfined compression strength (UCS) tests were carried out on the soil samples treated with two different polymer materials as well as the control sample. The results of UCS tests show an increase in the maximum dry unit weight by adding polymeric materials of RPP (Road Packer Plus) and CBR Plus (California Bearing Ratio Plus) to the soil. The results also show that polymeric materials improve the UCS of the soil that is dependent on the percentage of polymeric materials and curing time. According to the obtained results, treated samples indicate an increase in the strength with different percentages of RPP and CBR Plus as 32.143–91.30% and 55.84–168.56% for 0.019–0.1% and 0.0096–0.09% content of materials, respectively. The results show that the highest level of the stress and strain for RPP were 151.42 (kPa) and 4.6% (with addition of 0.1% RPP) and 167.13 kPa and 3.1% (with addition 0.09% CBR Plus), respectively.