We calculate the dynamic order parameter and dielectric susceptibility for the relaxor ferroelectrics like PbMg1/3Nb2/3O3, PbSc1/2Ta1/2O3 and Pb1−xLaxZryTi1−yO3. Calculations of temperature and frequency dependence of dielectric susceptibility show the existence of low- and high-temperature group of maxima obeyed to Vogel–Fulcher (VF) and Arrhenius laws, respectively. The VF law and non-Debye relaxation behavior as well as the stretched exponential law of susceptibility time decay were shown to be the consequence of random fields distribution which transforms single dipole Arrhenius and Debye laws into VF and non-Debye, stretched exponential laws, respectively. Comparison of observed and calculated characteristics of the relaxors is carried out.