In this contribution, we reported the investigation of natural rubber (NR) reinforced by silicon dioxide-graft-polyisoprene (SiO2-g-PIP) core-shell nanoparticle. First, the hydroxyl on the surface of the SiO2 nanoparticles was reacted with 2-methyl-2-[(dodecylsulfanylthiocarbonyl) sulfanyl] propanoic acid to produce trithioester-capped SiO2 (denoted as SiO2-CTA). SiO2-CTA was used as a nanoparticle chain transfer agent, and SiO2-g-PIP core-shell nanoparticles were synthesized via reversible addition-fragmentation chain transfer polymerization (RAFT). The results of FTIR spectroscopy and TGA showed that the grafting weight of the PIP block in SiO2-g-PIP was 2.1 wt%. SiO2-g-PIP and SiO2 were simultaneously incorporated into NR. The curing properties of the NR compounds showed that the vulcanization rates of the NR/SiO2-g-PIP compounds were much higher than those of NR/silica compounds. The results of scanning electron microscopy showed that SiO2 microdomains in the NR/SiO2-g-PIP vulcanizate were much better disperse and distribute than SiO2 microdomains in the NR/SiO2 composite. The filler-rubber interaction of the NR/SiO2-g-PIP composite endowed the composite with improved mechanical properties. POLYM. ENG. SCI., 59:1167-1174 2019. (c) 2019 Society of Plastics Engineers