Silicon (Si) can enhance the resistance of plants to many abiotic stresses. To explore whether Si ameliorates Fe2+ toxicity,a hydroponic experiment was performed to investigate whether and how Si detoxifies Fe2+ toxicity in rice (Oryza sativa L.) roots.Results indicated that rice cultivar Tianyou 998 (TY998) showed greater sensitivity to Fe2+ toxicity than rice cultivar Peizataifeng (PZTF).Treatment with 0.1 mmol L-1 Fe2+ inhibited TY998 root elongation and root biomass significantly.Reddish iron plaque was formed on root surface of both cultivars.TY998 had a higher amount of iron plaque than PZTF.Addition of Si to the solution of Fe treatment decreased the amount of iron plaque on root surface by 17.6％ to 37.1％ and iron uptake in rice roots by 37.0％ to 40.3％,and subsequently restored root elongation triggered by Fe2+ toxicity by 13.5％ in the TY998.Compared with Fe treatment,the addition of 1 mmol L-1 Si to the solution of Fe treatment increased xylem sap flow by 19.3％ to 24.8％ and root-shoot Fe transportation by 45.0％ to 78.6％.Furthermore,Si addition to the solution of Fe treatment induced root cell wall to thicken.These results suggested that Si could detoxify Fe2+ toxicity and Si-mediated amelioration of Fe2+ toxicity in rice roots was associated with less iron plaque on root surface and more Fe transportation from roots to shoots.