Effect of non-rubber components on vulcanization kinetics of natural rubber was studied with the use of a Rheometer MDR-2000. The results show that the rate constants of induction period and curing period of natural rubber (NR) are greater than that of natural rubber extracted with acetone (NRE), and the activation energies of induction period and curing period of NR are lower than that of NRE. The activation energy of induction period of NR is reduced by16.9% and the activation energy of curing period of NR is reduced by 3.2% compared to the activation energies of NRE. The time tdis of NR is shorter than that of NRE at the same temperature. (c) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012