Vanadium (V) is a redox-sensitive element, and its valence is controlled by the environmental redox conditions. In
recent years, the advancement in MC-ICP-MS analytical techniques has enabled the precise identification of subtle V isotope fractionation in igneous systems. As a result, V isotopes have shown great potential in the study of high-temperature geological processes. Understanding the mechanism of V isotope fractionation during igneous evolution is fundamental to their application in high-temperature geochemical research. This paper reviews the research findings on V isotopes in igneous rocks and points out that mineral crystallization and oxygen fugacity are the main factors controlling V isotope fractionation. Studies have shown that the separation crystallization of silicate minerals can alter V isotope composition of the melt. Moreover, Fe-Ti oxides are key factors controlling V isotope fractionation, and their separation crystallization can lead to an increase in the δ51V value of the residual melt. Additionally, while previous studies suggested that the V isotopes of primitive basalts are not sensitive to changes in oxygen fugacity, recent views indicate that there is recognizable V isotope fractionation at lower degrees of partial melting and higher oxygen fugacity. Based on this, this paper summarizes the applications of V isotopes as follows: in tracing crustal evolution, V isotopes have allowed to establish a close link between felsic continental crust and plate tectonics; in constraining the formation of layered intrusions, V isotopes reveal an evolutionary path from primitive magmas to highly differentiated products; and in tracing mantle-derived magma sources, V isotopes suggest that partial melting and fractional crystallization jointly dominate the transformation of carbonate melts into alkaline basalts. These studies fully demonstrate the great potential of V isotopes in the study of high-temperature geological processes.