Arsenic (As) is an ubiquitous metalloid, widely distributed in the environment through both natural and anthropogenic pathways. A compartmented soil-sand culture system with rhizo-bag was used to investigate the dynamics of As and Fe species in the soil solution of rhizosphere under three water regimes in whole growing stages of rice plants. The results showed that flooded regime increased significantly concentrations of arsenite and arsenate at booting stage and grain-filling stage (p<0.001, the highest concentration: 2.67 mg·L−1) comparing with other two water regimes, unflooded and flooded-unflooded. There were significantly positive correlations between As and Fe species in soil solution of rhizosphere, between As concentrations in iron plaque and amounts of iron plaque formed as well.