Serpentinization of peridotites is a non-negligibly important geologic process in the oceans, which has attracted widespread attention in recent years. Serpentinization of the oceanic peridotites occurred largely in tectonic settings of mid-ocean ridges and convergent margins. A typical abyssal serpentinite is made up of serpentine minerals ± magnetite ± talc ± brucite ±amphibole. The three dominant species of serpentine minerals are lizardite, chrysotile and antigorite. Serpentine textures under the polarizing microscope can be divided into three categories: pseudomorphic textures, non-pseudomorphic textures and transitional textures. The physical properties of abyssal peridotites are strongly modified by serpentinization: serpentinization is responsible for a strong decrease in density and seismic velocities, furthermore, the magnetic properties of peridotites are also strongly affected by serpentinization; in addition, serpentinization of peridotites also changes the rheology of the altered rocks. The discovery of ultramafic hosted hydrothermal systems further arouses the interest of researchers in serpentinization of oceanic peridotites. Vent fluids associated with serpentinization of peridotites contain high concentrations of H₂ and CH₄. Serpentinization is an exothermic reaction and can drive hydrothermal circulation, resulting in the occurrence of low-medium temperature hydrothermal system like Lost City.