From the perspective of popular science, this chapter aims at providing a basic understanding of the concept and evolution of Biomaterials. Traditional biomaterials are introduced with emphasis on the concepts, merits, and drawbacks of metals, polymer, ceramics, and composites used in biomedical science. The importance of surface modification is described, and the general behavior as well as cell interactions with artificial materials is discussed. Plasma immersion ion implantation, which is one of the important and common techniques, is described in detail. In the last part of this chapter, typical applications of biomaterials and possible future development are presented.