The objective of this research was to investigate the role of steelers` dust as a catalytic reagent in H₂O₂/steelers` dust system. In acidic condition, FeO and Fe₂O₃ in steelers` dust could be dissociated to produce ferrous ion and ferric ion, which reacted with hydrogen peroxide to produce hydroxyl radicals and then degrade 4-chlorophenol. The batch experiments showed that 0.51 5mM 4-chlorophenol and its oxidation intermediates could be totally decomposed within 60 minutes by 1g/L steelers` dust and 0.485mM hydrogen peroxide at pH 2.7. The removal of 4-chlorophenol in H₂O₂/steelers` dust system was affected by the concentration of hydrogen peroxide rather than the dose of steelers` dust. The rate constants in the simplified kinetic model proposed in this study were estimated by fitting to the experimental data obtained in H₂O₂/steelers` dust system. Using the estimated kinetic rate constants, the simulation of 4-chlorophenol, ferrous iron, hydrogen peroxide, and hydroxyl radical concentration was performed. The predicted concentrations of 4-chlorophenol and hydrogen peroxide corresponded to the actual concentrations. The concentration of ferrous iron tended to be underestimated while that of hydroxyl radical was overestimated by the proposed model. For the experimental conditions conducted in this study, a value of 0.3mM hydroxyl radical could be suggested to calibrate the overestimated prediction.