Provided is an optical transponder that receives a tributary signal such as a SDH/SONET signal, a GbE (Gigibit Ethernet) signal, and a SAN (Storage Area Network) signal in a WDM (Wavelength Division Multiplexing) transmission system and a SDH (Synchronous Digital Hierarchy)/SONET (Synchronous Optical Network) system, and more particularly, to an optical transponder having a switching function. The optical transponder having a switching function includes: a switch changing a data path of an input tributary signal from a plurality of channels (ports); an STM-64/OC-192 mapper/demapper mapping the tributary signal switched to a different data path by the switch to an STM-64/OC-192 signal or demapping the STM-64/OC-192 signal to the tributary signal; and a transmission delay time compensator compensating for a differential delay caused by a transmission route difference on an optical fiber link when the STM-64/OC-192 signal is demapped to the tributary signal.