The silicone elastomers offer in our days new perspective for the construction in the precision engineering and in the medicine because of their special mechanical, electrical, optical and chemical properties. Since the essential material parameters like storage modulus and loss modulus depend on temperature and frequency explicit it is important for simulations to know these characteristics. This report is about determining of relaxation behaviour of silicone rubbers and about finding the mathematical relation to describe time-temperature equivalence of silicone elastomers. As conclusion we can declare that the common used Williams-Landel-Ferry equation to describe temperature and time dependent behaviour of polymers is not applicable for silicone rubbers.