To provide wavelength multiplexing transmission equipment capable of changing the internal connection path of a communication line corresponding to variation of a dynamic network configuration.

In the wavelength multiplexing transmission equipment, a plurality of input/output ports 1-N are provided for connecting communication lines to WDM optical transmission/reception modules 131-13n via a matrix switch 15. Also, a switch control circuit 16 and a communication port 17 for controlling the matrix switch 15 are provided. Thus the wavelength multiplexing transmission equipment is configured so as to change connection paths of the matrix switch 15 between the WDM optical transmission/reception modules 131-13n and the input/output ports 1-N according to externally input information related to the communication line connection.