We propose and demonstrate a novel variable PDL emulator based on a LiNbO3 modulator. The proposed emulator could vary the PDL values simply by adjusting the bias voltage of modulator. The results show that the proposed PDL emulator could generate a wide range of PDL values (0 ～35 dB). The generated PDL value could be maintained within f 0.02 dB for >70 minutes. The wavelength dependency was about 0.03 dB in the range of 1520 nm ～1590 nm.