Innovated technique to inactivate microorganisms has been developed. This technique uses plasmadischarge in 2-phase (Air-Water). Dielectric Barrier (two phase) Discharging system is able to produce newoxidants for microorganisms. Products from discharging are HNO2, NO2, HNO3, NO3and ozone but manyother radicals can be generated as well. DBD water has low concentration of ozone (about 0.5mg/L), NO2,NO3(about 10mg-N/L, 20mg-N/L respectively) and lots of H+. These products play an important role inoxidation. Oxidation power by KI titration methods is approximately equivalent to 50mg-O3/L. Surprisinglystored DBD water could oxidize KI and maintain stable pH (about pH3) even after several days. Stored DBDwater for 5 days has also more than 4log disinfection power to E. coli. However, DBD water cannot be usedfor drinking water directly due to its toxicity. Additional process to neutralize pH and decrease toxicity mustbe applied.