Abstract: Several lab experiments were done to compare the effectiveness of three pretreatment technologies for Microcystis aeruginosa inhibition at the drinking water treatment (DWTP): NaClO, K2FeO4 and KMnO4. All three technologies showed effectiveness in varying degree to inhibit Microcystis aeruginosa, their performance increased with increasing concentration and time. However, Microcystis aeruginosa cell wall lyses was of concern at higher concentrations.