ZnO was synthesized by potentiostatic electrodeposition, characterize by XRD, SEM and EDX, and used as a catalyst for degradation of Reactive Blue 19 (RB 19) dye by non-thermal atmospheric pressure corona plasma discharge. The principle of degradation and the role of the catalyst were presented. ZnO improved the degradation rate by 2.35 times by enhancing decomposition of plasma-generated H2O2 into ⋅OH radical, which was found to be a major degradation reagent.