A set of equations is suggested to describe the kinetics of degradation of organic compounds applied tosoils and the kinetics of growth of the involved microorganisme:where x is the concentration of organic compound at time t, m is the number of forcroorganisms capableof degrading the organic compound at time t, while j, k, f and g are positive constaats. This model cansatisfactorily be used to explain the degradation curve of organic compounds and the growth curve of theinvolved microorganisms. A set of equations is suggested to describe the kinetics of degradation of organic compounds applied tosoils and the kinetics of growth of the involved microorganisme: where x is the concentration of organic compound at time t, m is the number of forcroorganisms capable of degrading the organic compound at time t, while j, k, f and g are positive constants. This model cansatisfactorily be used to explain the degradation curve of organic compounds and the growth curve of the involved microorganisms.