Biological effectiveness of any type of radiation can be related to absorbed dose versus linear energy transfer (LET) associated with the particular radiation field. In complex radiation fields containing neutrons, especially in fields of high-energy particles or in stray radiation fields, radiation quality factor can be determined using detectors which response depends on LET. Recombination chambers, which are high-pressure, tissue equivalent ionization chambers operating under conditions of initial recombination of ions form a class of such detectors. <p> </p>Recombination Microdosimetric Method (RMM) is based on analysis of the shape of current-voltage characteristic (saturation curve) of recombination chamber. The ion collection process in the chamber is described by theoretical formula that contains a number of coefficients which depend on LET. The coefficients are calculated by fitting the shape of the theoretical curve to the experimental data. <p> </p>The purpose of the present project was to develop such a program for determination of radiation quality factor, basing on calculation of dose distribution versus LET using RMM.