Multi-agent simulation (MAS) is a widely used paradigm for modeling and simulating real world complex system, ranging from ant colony foraging to online trading. The performance of existing MAS software, however, suffers when simulating massive-scale multi-agent systems on traditional serial processing processors. In this paper, we propose an FPGA-based framework for massive-scale grid-based MAS. Memory interleaving, parallel tasks partition, and computing pipeline are adopted to improve system throughput. A classical MAS benchmark, Conway's Game of Life, is used as a case study to illustrate how to map grid-based models to our MAS framework. We implemented it on a Xilinx Virtex-5 FPGA board and achieved a speedup of 290x with two million agents, compared to the C implementation. © 2011 IEEE.