The application of microwave measurements to the characterisation of rubber compounds vulcanisation is considered. The behaviour of mechanical and microwave (20 GHz) dielectric parameters during vulcanisation was investigated for rubber compounds with different concentrations of active and non-active carbon black. An increase of concentration or activity of carbon black results in the increase of both dielectric permittivity e'(T) and loss e" (T) and in the increase of torsion modulus as well. The start of the vulcanisation reaction is indicated by an increase of dielectric permittivity and torsion modulus in all investigated vulcanised compounds with carbon black. While for compounds with non-active carbon black the vulcanisation can be better indicated by the e' (T) anomaly, for compounds with active carbon black it is more clearly seen by the change of e" (T) behaviour.