In this letter, two kinds of continuous wavelength-tunable light sources are achieved and investigated experimentally using a self-seeding reflective semiconductor optical amplifier (RSOA). Over 40 single mode wavelengths with 100 GHz spacing are generated by setting the parameters of the wavelength selective switch. The peak power of each wavelength reaches over 0.2 dBm with the signal-to-noise ratio (SNR) > 35 dB. The proposed schemes are appropriate for multi-wavelength-tunable light sources; the maximum number of wavelengths generated can reach to 4.