Abstract: In heterogeneous multi-core architecture, a large number of shared last level cache (LLC) space is occupied by GPU applications, leading to the system performance degradation. This paper presented a LLC buffer management strategy based on heterogeneous multi-core, buffer-for-GPU (BFG). A buffer was added on the side of LLC to filtrate streaming requests of GPU. Cache insensitive GPU messages directly accessed to buffer instead of accessing to LLC. Then, for different characteristics of CPU applications and GPU applications, a reasonable replacement strategy was adopted to increase the cache hit rate. Resulst show that compared with the traditional heterogeneous multi-core structure, the LLC buffer management strategy improves the CPU's and the GPU's IPC by 2.48% and 9.30% on average, and improves the hit rate of CPU applications by 70.45% on average. BFG can effectively filter the GPU requests, vacate space to CPU applications, and improve system performance.