Abstract: A pot experiment was conducted to study the effects of plant growth regulator GA₃ and metal chelate EDTA on enhancing the remediation of Pb contaminated soil, and the detoxification mechanism of Lolium perenne grown on Pb contaminated soil at 250 and 500 mg·kg^-1. The results showed that cell wall deposition and vacuolar compartmentalization played important roles in the detoxification of Pb in L. perenne shoot. The addition of EDTA alone increased Pb concentration in plants and Pb proportions in soluble fraction and organelles fraction, and enhanced the toxicity of Pb to plant, leading to the significant reduction of the plant biomass (P<0.05). Foliar spray of lower concentration of GA₃(1 μmol·L^-1 or 10 μmol·L^-1) alone significantly increased Pb accumulation by L. perenne (P<0.05), but Pb proportions in soluble and organelles fraction were decreased, which alleviated the adverse effects of Pb on plant, thus improving the growth of plants (P<0.05), with 1 μmol·L^-1 GA₃ being the most effective. In contract, the addition of 100 μmol·L^-1 GA₃ decreased Pb concentration in L. perenne, but increased the proportions of Pb in soluble fraction and organelles fraction, resulting in the reduction of plant biomass. Lower concentration of GA₃ might alleviate the adverse effects of Pb and/or EDTA on plant, since the biomass amounts in the different treatments were in order of GA₃ alone of lower concentration > GA₃ of lower concentration+EDTA > EDTA alone. The combination application of low concentration of GA₃ and EDTA showed a synergistic effect on the Pb accumulation in L. perenne (P<0.05). Especially, Pb concentration in shoot and Pb extraction efficiency reached 1250.6 mg·kg^-1 and 1.1%, respectively, under the treatment of EDTA+1 μmol·L^-1 GA₃ on the Pb 500 mg·kg^-1 soil. Therefore, the application of 1 μmol·L^-1 GA₃ along with EDTA appeared to be a potential approach for phytoremediation of Pb contaminated soil.