This paper presents an integrated simulation system to be used for the design and evaluation of distributed computer control systems. The simulation system is comprised of Communication Performance Evaluation Module, System Reliability Evaluation Module and Control Performance Evaluation Module. Different from conventional all-software approaches, dedicated hardware facilities such as a parallel multimicroprocessor system for real-time simulation of controlled system dynamics and a mimic communication system are used advantageously to achieve best overall economy of simulation in conjunction with software simulation modules. The features of the proposed of simulation system as applied to several distributed computer control systems with different system architectures are described.