We study modulation of Galactic Cosmic Rays (GCR) particles based on the Parker’s Transport Equation, which describe a four major processes: convection, diffusion, drift and adiabatic cooling responsible for modulation of the GCR flux. We taking into account the physical parameters characterizing the GCR modulation in the interplanetary space; as radial and tangential components of the GCR anisotropy in various sectors of the heliospheric magnetic field (HMF) and module B of the HMF and changes of drift effect of the GCR particles with solar activity (SA). Our approach is the implementation of two independent parameters (proxies), γ and ν in different periods of SA. The solutions of numerical model are compared with the variations of the GCR measured by NMs. We show the existence of a changing delay time (DT) between the changes of GCR intensity and the parameters characterizing SA. We obtained different DTs in considered Solar Cycles from 20 to 23. We conclude that the calculated DT is compared with observed DT and is a very significant parameter for study modulation of GCR.