摘要： For two-dimensional (2D) materials, an attractive feature is that all the atoms of the materials are exposed on the surface. Thus tuning the structure and properties by surface treatments becomes straightforward. Similar as graphene, the nearly zero-gap character of silicene hinders its applications in electronic and optoelectronic devices. In the case of graphene, functionalization through hydrogenation, halogenation, oxidation, have been widely explored in order to modify the electronic structure of graphene. However, the stable aromatic π-bond network of graphene makes it very inert and difficult to bond with foreign atoms. For example, hydrogen atoms on graphene usually form clusters instead of an ordered structure. In contrast, silicene possesses hybrid sp2-sp3 bonding, which is more readily to be modified or functionalized. Since the early stage of silicene research, theoretical investigations on the hydrogenation, halogenation, and oxidation of silicene have been widely reported in literature. Recently, increasing experimental successes have been achieved on functionalization of silicene. It is now imperative to review the progresses in the fast-growing field. In this chapter, we will discuss hydrogenation, halogenation oxidization individually. In each section, we first describe those theoretical predictions and then illustrate recent experimental successes. Finally, we will give some overview and outlook of this field.