The azo chromophore anchored polyurethanes were synthesized by azo coupling of 4 nitrobenzenediazonium tetrafluoroborate and reacting the obtained 6 nitrobenzothiazole 2 diazoniun tetrafluoroborate with polyurethane in dimethylforamide in the presence of HAc and its sodium salt. The polyurethanes were characterized by IR, UV Vis and 1H NMR spectra. The method has the advantages of simplicity and facility in preparing polyurethane NLO materials with different chromophores.