This thesis describes the design and implementation of a general purpose microprogram development system which consists of a microprogram meta-assembler and a simulator. The meta-assembler is used for microprogramming, and the simulator for testing microprograms. The meta-assembler, which is developed by Advanced Micro Devices(AMD), is modified for the construction of an interactive simulation system. The simulator has special functions - such as state display, state modification, address stop, interactive functions, etc. - to simulate microprograms efficiently. In addition to, some speed-up factors are analyzed and improved. To integrate the meta-assembler and the simulator, a loader is designed. The microprogram development system is used to develope the microprograms of the IBM 370/138 emulation system.