Amino-terminated and carboxylic acid containing aqueous-based polyurethane (PU) dispersion was prepared by a conventional NCO-terminated PU prepolymer process by using isophorone diisocyanate (IPDI), polypropylene glycol-2000 (PPG-2000) and 2,2′-dimethylolpropanoic acid (DMPA) as the key raw materials. A new curing agent, tri-glycidyl phosphate (POG) was prepared from a substitution reaction of phosphorus oxychloride and glycidol. A single-component self-curable aqueous-based PU system is obtained from an addition of POG into aqueous-base PU dispersion and its curing reaction occurred among POG oxiranes and PU amino groups immediately after hydrophobic POG diffused into PU particles (as polymeric micelles). The cross-linked PU resins were resulted on drying at ambient temperature. Original PU dissolved into THF and ethanol. And its gel content increased to 90.1% and sample loss in ethanol decreased to 9.2% of this self-cured PU system with 5.0 phr POG. The limiting oxygen index (LOI) value is 20 of original PU and its LOI reached to 27 of this same self-cured PU system. The improved mechanical and thermal properties of those self-cured PU resins were evaluated, respectively in this report.