Modern hydrothermal activity is a progress of exchanging heat and mass between oceanic lithosphere and ocean which commonly developed among active oceanic plates margins and intro-plate volcanic center.

Judging chemical reactions formed native sulfur with equilibrium constant in seafloor hydrothermal activity off Kueishantao at northeast of Taiwan island;

The implications and the results of the transition metal isotopes in the study of seafloor hydrothermal activity have been introduced.

The history of studies on seafloor hydrothermal activity and several important issues being researched at present are reviewed.

A total of 1 264 sulfur isotopic values for modern seafloor hydrothermal sediments from different hydrothermal fields have been collected.

In this paper,the geologic background of the Mid-Arctic Ridge and the submarine hydrothermal activity features on the Gakkel Ridge are introduced,and the research prospects are made from the viewpoint of geophysics,marine mineral resources,marine chemistry,marine thermal structure and marine biology.