An important observation of comparative behaviors of As and Sb during coagulation with FC is that, Sb(V) removal are much more difficult than As(V), but the removal of Sb(III) is relatively preferable to As(III). Summarily, the removal efficiency of various As and Sb species during FC coagulation at ambient pHs is arranged in the orders of As(V) > Sb(III) > As(III) > Sb(V). Therefore, pre-oxidation is usually helpful for arsenic removal with CFS, while for antimony removal, keeping the natural water under anoxic conditions is more favorable.