Abstract: The composition of hot fluids that exit at vent fields reflects a number of factors including the initial seawater composition, the composition and structure of host rock, and the characteristics (depth, size, and shape) of heat source. Meanwhile, the addition of magmatic volatiles in various tectonic environments may affect fluid compositions. Two main types of hydrothermal deposits, including metal sulfide chimneys formed by high temperature fluid and the metalliferous sediments derived from hydrothermal plumes, diffuse flows and the mass wasting of preformed metal sulfides, may form when the vent flow rises from seafloor. The formation of sulfide chimneys is dominated by the mixing ratios of seawaters and hydrothermal fluids, and generally features with a typical two-stage-model. During stage 1, vent fluid mixes turbulently with seawater, resulting in precipitation of a ring of anhydrite. While in stage 2, the copper-iron, and iron sulfides begin to precipitate and plate the inner chimney wall. This model can also be observed on a larger scale, such as in TAG hydrothermal mounds. The biological processes are believed to play a key role in the hydrothermal mineralization including the formation and alteration of chimneys and diffusion of plumes. Nowadays, much attention is concentrated on the exploration and mineralization of Lost City field and ultraslow-spreading ridges. The researches of the first two issues may deepen the understandings of the early earth and life evolution, and the researches of the last one may enrich the mineralization theory and facilitate investigations of larger scale sulfide deposits.