The propagation time of electromagnetic pulse(EMP) through nonmagnetic stationary laboratory Xe plasma was investigated by using network analyzer, with EMP frequency of 9—11 GHz. The research indicates that the propagation time of EMP through plasma will be less than that through the same distance in vacuum when the plasma density is in the range of 0.65—1.43×1011 cm-3，and the time delay will be a minimum at ne1.10×1011 cm-3. In this range of plasma density, the dispersion relation of electromagnetic wave in Xe plasma without magnetic field will be invalid.