The purpose of this study is to propose a concept of framework for constructing an autonomous distributed system, and to evaluate effectiveness of proposed idea by developing software tools based on the concept. In the framework of this study, autonomous distributed system consists of a set of agents which is autonomous processing elements having identical data and identical goal of performance. Each agent preforms decision procedure to achieve its goal with exchanging messages and informations each other on computing environment in which several computers are connected by information link. To improve flexibility of an autonomous distributed system, the concept of transportation of agent that agent can be dynamically moved on hardware environment and the concept of dynamic extension of agent that function of agent can be dynamically extended by merging two agents are introduced in this study. And to realize the autonomous distributed system based on the concepts, software tools have been developed. These software tools are coded by C language and implemented into the computer system that several UNIX based EWS is connected by information link.