This study is to develop a composite material sleepers based on synthetic resin instead of neck sleepers applied to martial bridges. For this purpose, the properties of various polyols with various functional groups for the improvement of strength were evaluated, and the aim was to improve the physical properties by modifying isocyanate and expanding the reaction sites. The physical properties of polyurethane were evaluated according to the type and content of additive for the improvement of the physical strength of polyurethane