Based on a single semiconductor optical amplifier (SOA),simultaneously wavelength conversions (WC) of two input data signals are accomplished. The input signals are return to zero (RZ) code with extinction ratio deterioration,the “0” code with lower optical power (not zero),and its polarization state is orthogonal with “1” code. Using the intensity and polarization correlation characteristic of four-wave mixing on SOA,by carefully setting the polarization relationship between one signal and the other,the two modulation signals information are copied to separately the idler of four-wave mixing (FWM). The experimental results show that the output of two-way signal with wavelengths converted has a good extinction ratio (ER).