Lately, beams of heavy charged particles, e.g., protons and carbon ions, have found wide application in radiation therapy of oncological diseases owing to the fundamental possibility of qualitative im-provement of the spatial dose distributions when compared to sources of electrons and γ-rays conven-tionally used in radiation therapy, which makes it possible to radically decrease the radiation absorbed dose of the undamaged regions of the tissue adjacent to a tumor. In this paper a results of computer simulation are compared with experimental data for carbon ion carbon ion ranges in homogeneous phantoms using the RTS&T, FLUKA and MCNPX Monte Carlo multi-particle particle and ion transport code systems. Calculations of the main microdosimetric characteristics for cellular structures placed in homogeneous water phantoms are shown: average dose, linear energy transfer (LET), relative biological efficacy (RBE) and biological dose based on the Microbiological Kinetic Model (MKM) within software complex RTS&T. Calculations were made for the beam of 12C6+ ions with the energy of 454 MeV/u. Experimental data were obtained at the Temporary Radiobiological Stand of the U-70 accelerator complex at the Institute of High Energy Physics NRC "Kurchatov Institute", Protvino.