The influence of current density, electrolysis time, pH, Cl^- and SO₄^2- concentration on the inhibition of Microcystis aeruginos was investigated by Boron-doped diamond plate electrode. Algal cell morphology before and after electrochemical treatment were observed. The results show that the four factors had significant effects on the inhibition of algal cells. The inhibition of algae increase with the increase of current density and electrolysis time, which are good at 17 mA/cm² because of leading to the rupture of algae cells and outflowing of intracellular substances. Completed inhibition of algae could be obtained after 20 minutes. More than 20 minutes Electrolysis time have no obvious effect on the inhibition of algae. Completed inhibition of algae could be obtained under the initial pH in neutral and acidic conditions. The inhibition of algae increase with the concentration of Cl^- and SO₄^2- in the solution. The concentration of Cl^- of 6 mg/L could completely inhibit the growth of algae cells. The algal solution without chloride ion continue to grow after 4 days.