CPU/GPU heterogeneous computing embraces a rapid development in recent years. Considering that there are huge differences between CPU and GPU, CPU/GPU heterogeneous computing still faces many challenges. Therefore, collaborative features of fine-grained and coarse-grained parallelism are necessary to be explored in software designing. This paper takes a comprehensive study both on the CPU/GPU heterogeneous cluster's hardware and program execution characteristics. After performing OSU Micro-Benchmark (OMB) test on the TH-1A system, we got the communication bandwidth of inter nodes, intra nodes and memory access latency results between CPU and GPU. Finally, we designed experiments to complete IS and FT benchmarks of NPB suite on TH-1A. The results showed that we can get desired results on CPU/GPU heterogeneous cluster when the problem was computation intensive and with relatively large problem scale. The results also provide practical principles for designing parallel computing model of CPU/GPU heterogeneous cluster in our future work.