Abstract: This paper describes a two dimensional random pulse generator which createsa pulse amplitude spectrum with random distribution of time and statisticallyuniform distribution of amplitude. Besides, a high resolution stable pulse (referencepeak) is also produced just beyond the high end of the spectrum. This generatoris designed to replace the radioactive source in testing MCA or computerized dataacquisition and processing system. The shift of channel address and the resolutionof pulse amplitude of MCA can be measured precisely and easily by this generatorat high input pulse rates.