Persulfate (S_2O_8^(2-)) oxidation has recently been used to remediate soil and groundwater contamination.Persulfate is a strong oxidant which can be activated by initiators to produce more powerful sulfatefree radicals (SO_4^-‧) to degrade contaminants effectively. In this article suitable target compounds forpersulfate oxidation, the principles of persulfate activation, and the development of sustained-releasepersulfate materials are introduced to help readers better understand persulfate oxidation.