The biodegradation of solid wastes plays an important role in the integrated systems of waste management. To obtain the optimal values of such process parameters, as residence time, temperature, oxygenation, the accurate knowledge about process dynamics and kinetics is crucial. The kinetic model of biological oxidation of organic wastes has been presented in this paper. Kinetics of microbial decomposition of organic substances has been described by Maser equation. The satisfactory time courses for substrate (CODtot and CODlph) and biomass concentration (RNA) have been achieved. The changes of basic parameters as pH, COD, BOD5 and biomass have also been presented.