Agent-based groupware, such as the WorkWeb System, is a promising approach for open and distributed business process and workgroups. This approach introduces agents for the interface between human and the business system, and agents that coordinate multiple jobs, people, and organizations. However, deployment of agent-based groupware is very difficult, since introducing agents changes many people's working environments, and the effect of agents is difficult to demonstrate. Human behavior is also an important key to the success of agent-based groupware. If many people do not obey instructions from agents, the system, of course, does not function. However, we do not know how rigidly people should obey agents. To solve these problems, we take an approach to give a simulator that can simulate agent's behaviors and people's behaviors with some typical user models. This paper gives the simulation model, describes a prototype of the simulator, and discusses database support for the simulator.