Plasma irradiation into water for supplying to plants was employed to improve a growth rate of plants and inactivation of bacteria in bed-soil.Brassica rapa var.perviridis (Chinese cabbage;Brassica campestris)was used as a specimen and was cultivated in pots filled with artificial soil including chicken droppings as a fertilizer.The water was recycled once a day from drainage water pool to the bed-soil in the pots.A magnetic compression type pulsed power generator was used to produce discharge under the water with 250pps in repetition rate.