This paper presents an electric vehicles (EVs) operation simulation system based on multi-agent system using Java Agent DEvelopment Framework (JADE) for various studies on EVs. Most players, such as the government, the power grid, the electric vehicle owners, charging station operators and parking lot operators, involved in the EVs operation could be studied in this simulation system. Moreover, this simulation system allows users modifying existing agents and adding new agents to expand it due to its open architecture. We discussed the design of this simulation system in detail. Finally, a simple electric buses case was simulated to test the functionality of the simulation system.