Abstract: The tectonics of Chinese mainland is very complex, with frequent intraplate strong earthquakes and magmatic activities, and the dynamics of these phenomena has attracted considerable attention in the geoscience community. Seismological observations over the past decade have revealed the ubiquitous presence of a low-velocity layer (LVL) atop the mantle transition zone in Chinese mainland and its adjacent regions, which is generally attributed to partial melting induced by volatiles such as water. This paper systematically reviews the distribution, structure, formation, and dynamical characteristics of the detected LVLs in Chinese mainland and its adjacent areas. It focuses on the role of these LVLs in tectonic evolution, including plate subduction, secontary mantle plume origin, seismic activity, and intraplate magmatism, and provides an outlook on future research directions concerning the LVLs. Through this comprehensive review, we aim to deepen the understanding of the partially molten LVLs atop the mantle transition zone in Chinese mainland and its adjacent regions and to promote further development of related research.