Today, many scenarios are described for envisioning sustainable society such as the IPCC's Emissions Scenarios. These scenarios often employ simulators to provide a basis for their descriptions. However, existing scenarios do not explicitly describe the relationship between scenario document and simulators, e.g. its simulation conditions. This spoils reusability of scenarios. We propose a scenario design methodology to describe sustainable society scenario efficiently and effectively. We are developing Sustainable Society Scenario (3S) Simulator to support scenario design process. This paper proposes a method for making new scenario variants efficiently by reusing existing scenarios and simulators. In order to realize proposed method, we define a structural description method of scenarios for connecting scenarios with their simulators dynamically and we develop a data managing tools as components of 3S Simulator to modify scenarios by using proposed method. In a case study, scenario structure including simulator is clearly represented and we succeeded in describing new sub scenario easily by reusing existing scenario and simulator.