Relationship between exo-electron emission currents and statistical delay of glow discharges of ac-PDP was investigated by measuring exo-electron currents. The currents were measured as a function of time and doping elements. The measured results indicated that the exo-electron currents decrease exponentially with time, while the statistical delay increases with time. The results demonstrate that the statistical discharge delay is inversely proportional to the currents of exo-electron emission from MgO film in a time interval of 1 to 10 ms. (C) 2009 Elsevier B.V. All rights reserved.