Abstract: The routers on chip, which adopt packet-connection circuit switching, establish the links by sending a request packet and transfer data by circuit switching. Conventional routing algorithms are not suitable for the new features of Network on Chip (NoC) system based on packet-circuit switching. According to these new features, this paper proposes a new routing algorithm, namely Retrograde-Turn (RT) routing algorithm, to improve the performance of the NoC network. Compared with the dynamic XY routing algorithm, the experiment results demonstrate that the new routing algorithm can improve the average throughput and the average latency by 26.7% and 11.6% at best, respectively.