Under flooded and anoxic condition, reduction of iron minerals in paddy soil and formation of iron plague on root surface in interface microenvironment cause arsenic to release and contribute to arsenic absorption. Characterizing mechanisms of how iron affect arsenic is an effective method for reducing absorption of soil arsenic into rice. This paper reviewed the advances at home and abroad in iron’s effects on arsenic. The effects are discussed from five aspects, including rice aerenchyma, redox potential of soil solution, species of iron mineral, organic matter and species of anions, and research prospects are also discussed in order to provide references for remediation of arsenic contamination in paddy soil and inhibition of arsenic absorption into rice.