A kind of viscose fiber fabric with permanent flame retardancy has been prepared by grafting polymerization of phosphorus and nitrogen-containing monomer, i.e. 2,2-dimethyl-1,3-propanediol acrylamide methoxyl phosphate (DPAMP) onto viscose fiber fabric (VF-g-DPAMP). The effects of the initiator concentration, DPAMP concentration, temperature, pH and time on grafting polymerization were studied, and the structure of VF-g-DPAMP was determined with Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy. The surface morphology of viscose fiber fabric and VF-g-DPAMP were studied by scanning electron microscope. The thermal property and fire retardant performance of VF-g-DPAMP were assessed by thermogravimetric analysis, limited oxygen index measurements and cone calorimeter test, respectively. The results show that DPAMP has been successfully grafted onto viscose fiber fabric, and VF-g-DPAMP has good char-forming ability and better fire retardancy. The pkHRR and THR of the grafted fabric decrease from 150 to 98 kW/m2 and 5.70 to 1.73 MJ/m2, respectively.