Abstract: The labyrinth of vertebrate inner ear contains the organs responsible for the senses of hearing and equilibrium. Research on the morphology and function of this delicate structure has a very long history. In recent years, the sophisticated high resolution X-ray computed tomography has been widely applied in the research on the labyrinth of fossil vertebrate inner ear. Based on multivariable statistic analysis and metrical comparison with the analogs of extant species, the activity pattern of the fossil animals can be predicted or estimated. From an evolutionary perspective, the semicircular part of the labyrinth, fenestra vestibuli and aqueductus vestibuli are very stable structure. The fundamental morphology and special arrangements of these structures keep unchanged since the first appearance of the tetrapods. The press release mechanism of the inner ear underwent very complicated convergent evolution. Press release foramens termed as fenestra cochleae, perilymphatic foramen, or aqueductus cochleae are not always homologous across different vertebrate groups. The elongation and curving of the cochlea also occurred many times. Snail-like curving, coupled with the development of the lamina spiralis ossea and lamina spiralis secundaria, occurred only in the clade consist of Dryolestoidea + Vincelestes + metatherians + eutherians.