SUMMARYThe paper is mainly about a novel organophosphorus flame-retardant N-1-chloroisopropyl alcohol -3-dimethylphosphonopropionamide. Dimethyl phosphate, acrylamide and epichlorohydrin were used as raw materials. The mechanisms of synthesis and molecule structure of the flame retardant were discussed. The fiber was treated using the pad-dry-cure-wash method. The limiting oxygen index value of the modified sample was 31%, higher than that of the sample treated with MDPA (Pyrovatex CP). After 50 laundry cycles, it still had some flame retardancy left. Thermogravimetry (TG) and Differentiate TG analyses confirmed that the flame retardant caused fiber to decompose below its ignition temperature and formed carbonaceous residue or char when exposed to fire. The treatment had an obvious effect on the denier of the fiber; the tensile strength of fiber slightly decreased, but that effect could be negligible.