Due to the rapid advancement of VLSI technology, functions of multimedia systems (e.g. MP3, image processing etc,) become more complex nowadays. Therefore, more complicated system architecture and powerful computing ability are required to attain real-time process. In order to fulfill the requirement of cost and efficiency, multimedia systems usually consist of processors, ASICs and other various components. Diverse real-time functions of multimedia system can be implemented via co-operation of these components. However, these components have the differences in area, efficiency, and cost. Accordingly, it is necessary to establish a useful method and tool to decide better system architecture. ¡@¡@The main objective of the thesis is to develop a decision tool of system architecture. Given the system specification and constraints of a multimedia system, it can quickly decide a good system architecture to satisfy the constraints in accordance with the system specification . Except for partitioning various functions and mapping functions to hardware components, the decision tool must implement scheduling and pipelining to fulfill resource constraints and reach the real-time requirement. A great deal of time and cost for implementing the multimedia system can be reduced by careful scheduling and pipelining. Besides, owing to the pressure of time to market in system development, we propose a series of design flow to speed up the design process. All decision tasks in the flow are finished by automatic or semi-automatic method to reduce the exhaustion of manpower and time. Finally, we make experiments with the proposed tool on several multimedia systems. The results show that the automatic process can conform to constraints which set up by system specifications and ensure the accuracy of the process.