By the method of capillary viscosimetry the influence of potassium bromide on the structural changes of bromide cetyltrimetylammonium (CTAB) were studied at temperatures 27, 35, 45, 50 and 60°C. The practical interest is caused by broad application of CTAB as the template from the composition nonporous materials. Despite of the works edited before in this paper based on the concentration dependences of the reduced viscosity were studied named as second critical micelle concentration (CMC2) in the temperature 27 – 60°C.