Аннотация:A theoretical study has been carried out of an active mode locking (ML) which arises in a solid-state laser with an acousto-optic modulator (AOM) utilizing a traveling sound wave. It is assumed that the AOM is located in a V-shaped resonator due to which diffractional feedback is produced in the modulator. The AOM transmittance has been found to be the function of time. The ML which arises in the V-shaped resonator is equivalent to that which is observed in lasers with the intracavity FM of the radiation. ML stability in the resonator with the AOM utilizing the traveling acoustic wave has been studied.