Current research issues on web services have come to center around flexible composition of existing services. Under the initiative of industry, flexible composition framework has been developed on a workflow model where flow of the processes and bindings among services should be known beforehand. In short, its framework realizes flexible composition within the available services that are not widely opened. This paper focuses on two limitations of current web service composition. One limitation is that it's hard to represent multi-agent scenarios consisting of several concurrent processes because it is based on a workflow model. The other limitation is that once composed, web service cannot be reused or transferrd for other requesters, because there is no function to put the semantics on composite web service. To overcome these limitations, we have developed scenario description language Q, which enables us to realize a web service composition reflecting a multi-agent's context not as a workflow but a scenario. Furthermore, we developed a system that translates multi-agent scenario to DAML-S, and that registers the translated DAML-S as a new Web service. We also discuss the availability of our system for designing an application to C-Commerce and Digital Cities.