Rogowski coils have been used for decades for non-invasive current measurement when other probe, such as current shunts, current transformers are impracticable. The measurement of diode beam current in pulse power system under vacuum and high voltage are challenging task which requires development of Rogowski coil for specific applications. They operate in large radiation fields, under intense electron bombardment and at high di/dt. The Rogowski coil has been developed and calibrated to detect nano second pulsed currents from 10kA to 100kA with wide bandwidth and sensitivity. This paper describes Calibration of Rogowski coil used for measuring KALI-1000 pulsed power system[1] relativistic electron beam current. Rogowski coi designed and fabricated using damping resistor technique is also described. © 2011 IEEE.