Abstract: The experimental method and apparatus researching on ultra-wide spectrum(UWS) electromagnetic pulse(EMP) coupling through apertures have been established, the electric field of coupling through round holes was measured depending on different pulse width, different diameter and different depth. The method avoids the reflecting field and scattering field in a certain time window. The experimental results show that: for incident pulses of the same amplitude, the coupling field amplitude is inversely proportional to the incident pulse width and the depth of the holes, proportional to the diameter of the holes.