Many materials have been developed for biomedical applications, and many researchers still aim to develop biomaterials that have better properties than the currently-used ones do. In order to develop a new biomaterial, there are two basic approaches: one is the development of a pure biomaterial made of a single chemical substance and the other a composite biomaterial made of more than two different substances. The latter approach can be realized, for example, by coating a material with another one. In terms of corrosion and compatibility, this approach seems to have some advantages. For example, 1) a thin coat with anti-corrosion and good compatibility material will convert a corroded substrate, which has a unique and advantageous physical property, into a new anti-corrosion composite material. Therefore, the development of anti-corrosion coating-material can result in numerous new composite, and 2) it is nowadays very difficult to develop a pure material that has anti-corrosion materials. One of the candidate coating-materials is diamond-like carbon (DLC). In this paper, the author reviewed whether DLC has anti-corrosion, and furthermore explored the relationship between the physico-chemical properties and the production parameters of DLC applications in medical field.