Abstract: Soybean oil modified resins are widely used in many fields due to high bio-based content, environment friendly and comparable properties to those of petrochemicals. In this study, a series of UV-curable waterborne polyurethanes were successfully synthesized by modifying the epoxidized soybean oil, which bio-based mass fraction contents were more than 45%. Then their curing processes and physical properties were further investigated. The results showed that the synthesized resins could be cured quickly under UV irradiation. The final double bond conversion could reach 87.6% after 40 s irradiation. The cured films had perfect physical properties, such as, adhesion (0T), pencil hardness (3H) and flexibility (0.5 mm).