Abstract: An all solid-state high-voltage rectangular pulse generator is proposed. This generator consists of a Marx generator, a pulse forming line (PFL) and a magnetic switch (MS). As a power supply, the Marx generator discharges to the PFL through an inductor. The inductor should cooperate with MS since it influences the discharging process directly and determines the volt-second product of the MS and the pre-pulse over the load. The MS saturates at exactly the moment the discharging process ends. PFL discharges to the matched resistor load through the saturated MS and a high voltage rectangular pulse is obtained over the load. The designs of the Marx generator and the MS are introduced in this paper. Experiments under a single shot and repetitive frequency of 5 kHz are carried out. PSpice simulations with a simplified model of MS are carried out to verify the experimental results. The experimental result matches well with the simulation results. A rectangular pulse with 12.5 kV voltage amplitude, 250 A current amplitude, 46-ns rise-time, 220 ns pulse-width is obtained over the 50 resistor load.