Due to the environmental impacts of conventional soil stabilization materials, such as cement, ongoing efforts have been carried out by different researchers to find alternative economical materials for substitution. Biopolymers are environmentally friendly materials that are widely used in different geoenvironmental applications such as removal of heavy metals from contaminated soils, reduction of soil hydraulic conductivity, erosion control, and soil improvement. In this research the feasibility of using chitosan biopolymer for sandy soil stabilization has been studied. The effects of biopolymer content, curing time, and curing conditions have investigated using unconfined compression tests. The results indicated that incorporation of chitosan has the potential to increase the interparticle cohesion between the particles and considerable improvement of sandy soil mechanical properties. After initial strengthening of the soil, some strength reduction over time was observed due to the degradation characteristics of the chitosan. With regards to the curing condition, better performances at dry condition compare to the wet and saturated environment were achieved. In addition to soil mechanical properties, the pore plugging effect of chitosan biopolymer on highly permeable sandy soil has been studied in this study.