The 1:3, 1:2 and 1:3 chromogenic complexes of ion association of 1-(4-nitrophenyl)-3-(4-phenylazophenyl) triazene (NPPAPT) with cethyltrimethylammonium bromide (CTMAB), dodecyldimethylbenzylammonium bromide(DDMBAB) and cetylpyridinium bromide(CPB) were formed, respectively, in the presence of triethanolamine. All absoption spectra of chromogenic systems occurred red shift. Based on these chromogenic reactions, the critical micella concentrations of CTMAB, DDMBAB and CPB can be determined. The range for the determination and apparent molar absorptivity were investigated, the possibility for the...