Diglycidyl ether of bisphenol A (DGEBA) was cured with a new phosphorus-containing diamine, 1,4-bis(3-aminobenzoyloxy)-2-(6-oxido-6H-dibenz[c,e][1,2]oxaphosphorin-6-yl)phenylene II, which was derived from 2-(6-oxido-6H-dibenz[c,e][1,2]oxaphosphorin-6-yl)-1,4-dihydroxy phenylene and S-nitrobenzoyl chloride followed by hydrogenation. The structure of the synthesized phosphorus-containing curing agent II was confirmed through EA, IR, H-1-NMR, and P-31-NMR. The curing kinetics of the DGEBA/II system were studied by the dynamic and isothermal DSC method. Dynamic kinetic parameters were calculated by using the Kissinger and Ozawa＇s methods, respectively. Isothermal kinetic parameters, including k(1), k(2), m, and n, were determined by an autocatalytic mechanism proposed by Kamal. The model gives a good description of curing kinetics up to the onset of vitrification. The glass transition temperatures of cured epoxy (DGEBA/II) were 180 degrees C based on DMA and 170 degrees C by DSC, respectively. The onset decomposition temperatures (T-d onset) were 376 and 367 degrees C under nitrogen and air, respectively. Char yields at 700 degrees C were 38 and 18% under nitrogen and air, respectively. Limiting oxygen index (LOI) was 30, thus the phosphorus-containing diamine curing agent II eras found to impart flame retardancy to the cured epoxy resin.