Nonrenewable petroleum-based plasticizers are widely used to lower the viscosity of rubber compounds, improve processability and decrease cost. However, some popular petroleum-based plasticizers, such as aromatic oils, are considered to be carcinogenic due to the high polycyclic aromatic hydrocarbon (PAH) content. Therefore, renewable bio-based oil such as soybean oil (SO) is recently emerging as sustainable replacement for petroleum-based plasticizers in rubbers. This is done by modification of SO through the reaction with dienes including dicyclopentadiene (DCPD) converting the C=C double bonds in the SO into cycloaliphatic groups of higher reactivity. The effect of incorporation of modified SO in styrene-butadiene rubber (SBR), chloroprene rubber (CR) and butyl rubber (IIR) containing carbon black (CB), precipitated silica and their mixture and also different curing systems including sulfur, metal oxide and phenolic resin is investigated. Rheological, thermal, dynamic, mechanical and aging properties of rubber compounds containing modified SO are compared with those of virgin SO and a petroleum-based naphthenic oil (NO). Results showed that SO and modified SO can react with various additives such as curatives and silane coupling agent during the curing process and change various properties. Rubbers containing modified SO showed improved elongation at break and tensile strength, cure rate and aging resistance than those with NO and SO. Both SO and modified SO provided rubbers with better thermal stability and lower glass transition temperature than NO. Rubbers containing modified SO also showed dynamic properties suitable for manufacturing tires with better wet traction and lower rolling resistance, and also better abrasion resistance simultaneously compared with those with NO. It is shown that modified SO is a good environmentally friendly replacement for petroleum-based rubber plasticizers in rubber compounds along with improved performance of rubber products an