The hysteresis loss and thermomechanical behavior of a series of NR filled vulcanizates were studied. Rubber specimens prepared with four varying types of vulcanizate network systems were used, and the hysteresis and dynamic properties were measured. The heat buildup behavior was studied by compressive fatigue of solid rubber components. Relationships between heat generation of filled rubber vulcanizates and hysteresis loss, 100% modulus, loss compliance, loss modulus, filler loading and ambient temperature were examined. The heat buildup can be correlated to the dynamic mechanical behavior. A comparative study of different types of crosslink structures has been made in this study; from the results, we concluded that there are clear distinctions of heat generation behavior between crosslink structures. (C) 2000 Elsevier Science Ltd. All rights reserved.