In order to decrease response time and improve accuracy of high-pulse current measurement, a new kind of ns-range Rogowski coil with closed magnetic core is developed. Important parameters are calculated and designed according to electromagnetic theories. By using 50 Ω damping resistor, the parasitic high-frequency oscillations are improved at the front edge and back edge of the output voltage pulse. Pspice circuit analysis is employed to simulate the equivalent circuit of the Rogowski coil and good simulation results are obtained which correspond to theoretical design. Calibration experiments are carried out with 50 ns and 10 ns square pulse source, and results show that response time of the coil are 2.43 ns and 1.10 ns and sensitivity is 3.34 A/V. This coil is used to detect the current