This chapter reviews the studies of keratin-based biomaterials in the past and discusses the advancement of it in recent years. Keratin, as a protein-based biopolymer, possesses excellent biocompatibility and biodegradability. In addition, keratin has abundant disulfide bonds, which result in its unique and tough structure. However, the property also results in dissolubility, which causes difficult process ability. Over the past years, much research utilizes different methodologies to extract keratins. Different kinds of extraction methods affect the characteristics of keratins and give a wide variety of application forms. The features of different methods are discussed and summarized in the following.