Guangdong electricity spot market will officially run next year. As an important part of China's long-term energy development strategy, the “West-to-East power transmission” will cast a major impact on the Guangdong electricity market. Due to the network complexity of power systems, traditional economic theories cannot be well modeled for quantitative analysis. Multi-agent-based market simulation (ABMS) comprises autonomous agents and provides bottom-up modeling methods for such a complex system study and simulation. We apply ABMS to model and simulate the Guangdong electricity market, and then analyze the impact of “West-to-East” electricity power on the Guangdong market. Experiment results show that “West-to-East” power as the exogenous supply would reduce the average electricity price in Guangdong under normal system operation as well as compress the generation time of class B units.