Abstract: Epoxidized castor oil (ECO) was synthesized via epoxidation of castor oil (CTO). Then the prepared ECO was cured with toluene diisocynate (TDI) at 80℃ or 150℃ to obtain two kinds of cured cross-linking materials, and their molecular structures and comprehensive properties were studied. The results showed that the tensile strength, hardness and glass transition temperature of these two cured materials were improved significantly. Thermogravimetric analysis showed that all cured materials owned good thermal stability and the heating initial decomposition temperatures of cured materials were above 280℃. And the cured material obtained at 150℃ possessed typical carbamic-oxazolidone double cross-linking molecular structure.