In this paper, the electrical characteristics of Xenon gas discharging areal fluorescent lamp and the effect of improving of discharging efficiency at 55 inch diagonal size with a newly designed electrode shape named "double-T" are investigated. The investigation was based on a "T shape" electrode, which is well known in plasma discharging. The extending effect of the effective length of an electrode by a "double-T" electrode, which was applied to Xenon gas discharging areal lamp works well at 55 inches. This effect was induced to the plasma discharging of luminance of about 11,000 cd/m(2) at 1.1 kVrms driving signal. If the areal fluorescent lamp is divided into several blocks and applied dimming driving scheme each blocks, it can be applied to an eco-friendly backlight source due to the mercury-free and cost merit with a better contrast ratio in TFT-LCD area.