In saturated loose soil during an earthquake, the bonds between soil particles are weakened by cyclic shear forces. As a result, the pore water pressure increases between the weakened bonds of the soil particles, resulting in a liquefaction phenomenon in which the upper part of the sandy soil behaves like a liquid. When liquefaction occurs in the center of an urban area, several serious problems, such as building cracks and permanent land subsidence, can occur. Various methods, such as the ground compaction method and grouting method, have been attempted to prevent this liquefaction. Still, due to the enormous cost, difficulty in the construction process, and environmental destruction, methods to mitigate liquefaction based on reusable and eco-friendly materials have been attempted. This study conducted primary research to develop a method for preventing the liquefaction of biopolymer-treated soil. The resistance to liquefaction of the biopolymer-treated soil was observed through cyclic direct simple shear tests, and liquefaction resistance was evaluated quantitatively compared to untreated soil. Experiments were conducted for different vertical pressures, cyclic shear forces, and types of biopolymers to examine the liquefaction resistance.