A wavelength path communication node apparatus includes a wavelength path demultiplexer (321) which demultiplexes branched optical signals input to wavelength multiplexing ports into wavelength path signals, and outputs the wavelength path signals from wavelength demultiplexing ports corresponding to the respective wavelengths, a wavelength path multiplexer (322) which outputs wavelength path signals input to wavelength demultiplexing ports from wavelength multiplexing ports corresponding to the wavelengths of the wavelength path signals, a plurality of transponders (331) each of which converts a wavelength path signal input to a wavelength path transmission port into a client transmission signal to transmit the client transmission signal, and converts a received client reception signal into a wavelength path signal of a wavelength to output the wavelength path signal from a wavelength path reception port, a demultiplexing system optical matrix switch (323) which switches and connects the wavelength demultiplexing ports of the wavelength path demultiplexer and the wavelength path transmission ports of the transponders, and a multiplexing system optical matrix switch (324) which switches and connects the wavelength demultiplexing ports of the wavelength path multiplexer and the wavelength path reception ports of the transponders.