A novel modifier for bismaleimide (BMI), 2,4-di (2-allylphenoxy)-6-(2-naphthyloxy)-1,3,5-triazine (DAPNPT) with higher yield was prepared in one-pot by reacting cyanuric chloride with 2-allylphenol at first, and then by directly treating the adduct with 2-naphthol without separation. The chemical structure of the monomer was characterized by FTIR, mass spectrum, H-1 NMR and C-13 NMR. By means of differential scanning calorimeter, the thermo-homopolymerization behavior of DAPNPT was investigated and the results showed that DAPNPT did not polymerize at a range of temperatures from 50 to 250 degreesC. The properties of the DAPNPT-modified 4,4 ' -bismaleimidodi-phenylmethane (BMDPM) resins were also studied. The results showed that DAPNPT could effectively improve mechanical properties of BMDPM resin without greatly decreasing heat resistance of the resin. Better results were obtained when the molar ratio of DAPNPT/ BMDPM was 1:2.