Summary: This research was studied on the cure characteristics and mechanical properties of rubber compounds using vegetable oil as the processing aid in styrene butadiene rubber compound such as castor oil and jatropha oil in comparison with petroleum based aromatic oil. The quantities of the oils varied from 0 to 9 phr. The study showed that the cure characteristics in terms of maximum torque and torque difference tended to decrease with increasing concentrations of oils, while scorch time and cure rate index increased. Moreover, hardness and 100% modulus tended to decrease as increasing loading levels of the oils in the SBR vulcanizates while elongation at break increased. However, tensile strength was not significantly affected. For using the vegetable oils, we found that abrasion resistance and rebound resilience were better than those of aromatic oil, and also displayed high hardness. It could be concluded that the vegetable oils were better alternative processing aids compared to aromatic oil, which has been reported as carcinogenic.