In this study, multi-microprocessors system in which slave microprocessor is conrlected with master microprocessor bus through the DMA controller is designed by the use of four 8085 CPU. A high degree of processing efficiency could be obtained by making this system work parallel processing. The result of measuring relat ions bet ween working microproressor and system throughput was 70-80 percents lower than ideal value Master microprocessor takes charge of resource allocation and scheduling, common memory assigns communication between microprocessors and a store of common data. The met hod of detecting Pa rallelism from source Program composed by series is also suggested.