In order to compare the rust removal effects of commonly-used reagents for iron artifacts and to provide suggestions for the selection of reagents during iron artifact conservation, we carried out experimental studies using phosphoric acid, citric acid, tartaric acid and Na₂EDTA. Various kinds of samples such as rust powder, rust fragments, cast iron sheets and rusted cast iron sheets were used to quantitatively study the rust removal efficiency of the reagents and their corrosiveness to the iron substrate. The results show that 1) each of the reagents causes strong corrosion on the iron substrate, and that the corrosion rate is much higher than the rust removal rate but can be reduced by the addition of inhibitors; 2) among these reagents, phosphoric acid has the strongest ability to remove rust and it works well on both powder and fragment samples, but excessive amounts of phosphoric acid are needed to ensure the continuous rust removal, since a small amount of phosphoric acid has a passivation effect; 3) citric acid, tartaric acid and Na₂EDTA can dissolve the rust powder to some extent, but their efficiencies for rust removal from rusted fragments are very low. Consequently, phosphoric acid with a corrosion inhibitor is a suitable rust removal reagent in the conservation of iron artifacts.