[en] In the gravitational sector, we study the CPT violation and birefringence in gravitational waves. In presence of the CPT violation, a relative dephasing is generated between two circular polarization states of gravitational waves. This effect induces the birefringence of gravitational waves. Given the gravitational waveform modified by the CPT violation, we estimate the expected constraints on the CPT violation from Advanced Laser Interferometer Gravitational-Wave Observatory, Einstein Telescope and Laser Interferometer Space Antenna.