Disclosed is an optical ring network for burst data communication having a plurality of core nodes connected with each other through fiber links. Each core node comprises a demultiplexer for demultiplexing a received optical signal into a plurality of channels by wavelength, an add/drop section for dropping channels selected from the plurality of channels based on a control signal, a multiplexer for multiplexing and outputting the plurality of channels inputted through the add/drop section, a branching section arranged between the demultiplexer and the add/drop section for branching off channel portions from each channel, and a controller for recognizing destinations for frames with each channel modulated and outputting the control signal for dropping the selected channels to the add/drop section.