The present work focuses on the investigation of the influence of hard magnetic strontium hexaferrite filler on sulfenamide vulcanization of natural rubber. Both model compound and natural rubber vulcanization approaches together with a lot of instrumental methods have been used to follow the vulcanization kinetics. The results show that in the presence of hard magnetic fillers process of vulcanization is delayed due to changes in accelerator decomposition and ratio between the intermediates obtained. It may be stated that the hard magnetic filler acts as scavenger for some types of radicals formed during the vulcanization process. Changes in sulphidizing agent composition and its activity appear also.