Abstract: This paper introduces the advantage, purpose, principle and design of selfintegral Rogowski coil for nslevel current measurement. The response and distribute of Rogowski coil are discussed. The coil with a shield is treated as a distributed circuit, so that the toroidally wound coil acts as a delay line. The coil is calibrated. This coil could get the signal with rise time less than 2ns, value 10A～40kA, sensitivities about 1.4mV/A, pulsed width less than 200ns. The coil can be used in pulsed power technology for nslevel high current measurement.