Bis-azo-cyanocyclo-pentane, -hexane and -heptane are prepared and the kinetics of their thermolysis in several solvents are studied by differential scanning microcalorimetry. Unlike activation enthalpy and entropy, activation free enthalpy does not depend on solvent. Moreover its variation with temperature is quite small in each kinetic study temperature range. Thus Δ G # is given as an intrinsic stability characteristic of azo-nitriles. “Kinetic compensation effect” between Δ S # and Δ H # is discussed.