Abstract: A series of novel urethane-modified fatty amine used as waterborne epoxy curing agents based on oil and fat were prepared from polyamines and isocyanate group-terminated prepolymer synthesized from fatty alcohol polyoxyethylene ether (OE-6) and toluene diisocyanate (TDI).The optimum reaction conditions of prepolymer were as follows：the mixture of TDI and OE-6 in molar ratio 1.05∶1，at 45 ℃ for 2.5 h. The condition of polyamines extending chains were as follows：the mixture of polyamine and oligomers in molar ratio 1.2∶1，reaction temperature 40 ℃. After 3 h most of solvent was removed from the adduct，distilled water was continuously added to the adduct at 50—60 ℃ until solids content becomes 50%—55%，then urethane-modified fatty amine was synthesized. The structure of the product was characterized by FT-IR and 13C-NMR. The particle size analysis suggested that it could emulsify liquid epoxy resin. The properties of the two-component film of the urethane-modified fatty amine and liquid epoxy resin were measured，with flexibility 1mm，pencil hardness 3H，impact resistance 50 kg/cm.