The discharge characteristics of Ne+N-2 gas-mixtures were investigated for possible use in an ac Plasma Display Panel. The firing voltage increased with an increase in the N-2 concentration. When using a near ultra violet excited phosphor, (Ba,Sr)(2) SiO4:Eu, the luminous efficiency of Ne+10%N-2 gas-mixture discharges under 400 torr was about 20% better than when using the conventional phosphor. The UV intensity emitted from the gas discharges was found to increase with an increased N-2 concentration. Furthermore,. the UV efficiency increased with an increase in the N-2 partial pressure at a low N-2 concentration, yet became saturated at a high N-2 concentration.