Anthropogenic release of heavy metals (HMs) has resulted in a continuous buildup of HMs in agricultural soils. On one hand, uptake of HMs by crop plants may lead to food chain transfer to humans, and on the other hand, leaching of HMs with deep seepage may cause groundwater contamination. The objectives of this study were to assess the mobility of Cd, Cu, Pb and Zn under two common crop plants with different rooting systems including wheat ( Triticum aestivum ) with fibrous roots, and safflower ( Carthamus tinctorious ) with a taproot system in the arid soils of Isfahan, Iran. The study was conducted with undisturbed soil columns (Typic Haplocalcid) extracted from a wheat and a safflower field located in the same unit of soil type. The top 10 cm of half of the columns were artificially contaminated with Cd, Cu, Pb, and Zn at concentrations of 15, 585, 117 and 1094 mg kg -1 , respectively. Half of the contaminated and uncontaminated columns were planted with wheat and the other half with safflower according to their previous cultivation history. Leachate was collected continuously. After the crops were harvested, soil samples were collected at 10-cm intervals and analyzed for water- , HNO 3 - and DTPA-extractable metals. HYDRUS-1D and MACRO codes were used to model metal traort in the soil columns and also metal uptake by plants. Model parameters were estimated by inverse modelling using the SUFI-2 procedure. There was significantly increased metal leaching from contaminated columns. Plants enhanced the displacement of metals into subsoil. Safflower resulted in larger concentrations at deeper depths than wheat. Metal concentrations were significantly (p 0.05) higher in discharge and plants from contaminated than from uncontaminated columns. Because of discharge reduction in presence of plants due to trairation, total amounts of metals leached were in general larger in fallow than treatments with plants. The only exception was leaching of Zn from wheat columns, which was larger under plants than under fallow. Plants not only affected metal mobility through actual root activity, but also through effects on soil properties during previous cultivation history, as there were clear differences in metal leaching between wheat and safflower soils from fallow columns. These were metal-dependent indicating that the effects were not only related to soil structure by the root systems, but also to chemical soil properties. The calibration results with MACRO were similar to those obtained by HYDRUS with the difference that adsorption constants were much closer to the measured ones. This indicates that in HYDRUS, the adsorption parameters were underestimated in order to allow a deeper traort of metals which