This work is the experimental study for NO and NOx removal by utilizing non-thermal plasma. To apply to moving pollution source such as diesel automobile, we suggested the metal packed-helical wire reactor(MPHW) and measured properties of MPHW by varying the peak voltage, frequency, NOx concentration and flow rate for simulated NOx gas balanced with N₂. And then we compared these results with the results of cylinder-wire(CW) which was one of popularly used reactor in nonthermal plasma applications. The results of MPHW show fairly good NO and NOx removal rate compare with CW around above 20％. However, the power consumption of MPHW is larger than that of CW as much as around 2.5Watt in all range.