This paper describes the two-layer scalable wavelength routing optical interconnection network being developed in Tianjin University. The top layer of the network is multi- wavelength bi-directional optical bus, which has high bandwidth and low latency. The optical bus is made up of passive components, no wavelength-tunable devices have been sued. As a result, the optical bus has low communication latency that is mainly decided by the optical fiber length. The sub-layer of the network is single-wavelength ring, which has low communication latency and high-scalability. In each ring, a wavelength routing node is used for data transmission between the ring and the optical bus. Each node computer is connected to the ring using an optical network interface card, which is based on peripheral component interconnect bus. The communication latency inside the ring is decreased using synchronous pipelining transmission technique. The scale of the ring is mainly limited by the efficient bandwidth required by each node computer. The number of rings is mainly decided by the optical power of the laser diodes and the sensitivity of the optical detectors. If Erbium doped fiber amplifier is used in the optical bus, the scale of the network can be further developed.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.