Abstract: Two-dimensional (2D) materials represented by graphene have attracted great attention due to their important applications. Two-dimensional superconductors not only exhibit the rich physics of 2D materials but also have many potential applications, and constitute one of the frontier areas in superconductivity. In this article we review the history of this field, and especially introduce some representative 2D superconductors and the physical issues therein, and conclude with a discussion of future prospects.