A simple method based on time-resolved measurement of electrical discharge parameters, such as tube voltage and discharge current, is applied for experimental determination of electron temperature and electron density in the discharge period of various nanosecond pulsed longitudinal discharges, exciting high-power Cu + Ne-CuBr, He-Hg + , and He-Sr + lasers.Index Terms-Electrical discharge parameters, electron density, electron temperature, gas discharge, ionic metal and metal halide vapor lasers.