The majority of nonlinear optical effects arise in an optical fiber (OF) owing to nonlinear refraction, since at high light intensities the optical fiber refractive index is determined by its dependence on the intensity. For determination of coefficient γ for different OF types various methods are offered − both interferometric and non-interferometric. In this research we used pulse phase self-modulation (P-SPM) method with modulation via Mach-Zender modulator (MZM) by data 10 Gbit/s pulse sequence output of pulse pattern generator (PPG). The nonlinear coefficient of the various optical fibers types has been experimentally and with OptSim 5.0 simulation software studied. With the help of P-SPM measuring method the following parameters have been determined experimentally: nonlinear coefficient n2/Aeff and nonlinear refractive index n2; accordingly, n2/Aeff is calculated to be in the range 2.362∙10-10 - 5.552∙10-10 1/W, whereas n2 − in the range 2.88∙10-20 - 4.21∙10-20 m2/W.