With the rapid increase of the size of applications and the complexity of the supercomputer architecture,topology-aware process mapping becomes increasingly important.High communication cost has become a dominant constraint of the performance of applications running on the supercomputer.To avoid a bad mapping strategy which can lead to terrible communication performance,we propose an optimized heuristic topology-aware mapping algorithm (OHTMA).The algorithm attempts to minimize the hop-byte metric that we use to measure the mapping results.OHTMA incorporates a new greedy heuristic method and pair-exchange-based optimization.It reduces the number of long-distance communications and effectively enhances the locality of the communication.Experimental results on the Tianhe-3 exascale supercomputer prototype indicate that OHTMA can signifi cantly reduce the communication costs.