The present invention relates to A channel set up method of optical receiver with wavelength tunable filter such as an etalon filter in a TO type received wavelength-tunable optical receiver.According to the method of setting a channel in a wavelength-tunable optical receiver of the present invention, by circularly receiving communication channels within a predetermined temperature range, in which selectively receiving communication channel using two adjacent transmissive modes in the transmissive modes of a wavelength-tunable filter, it is possible to individually select and receive all communication channels with a predetermined temperature range. Further, it is possible to use all FP type etalon filters regardless of transmissive wavelength characteristics in at a specific temperature of a wavelength-tunable filter, so it is possible to reduce a manufacturing cost and power consumption of a product and increase thermal stability of a package.