This book includes seven chapters, each focusing on modern research into properties and applications of alginate. The first chapter elucidates the reader to the structural properties and applications of alginate, and additionally discusses future development targets in various fields. The second chapter gives an overview into fabrication of ALG- and S-ALG-based submicron- and nano-sized gel particles with a focus on protein encapsulation. The third chapter returns to analyzing the unique physical properties of alginate and its current and potential uses. The fourth chapter reviews the development of alginate hydrogel beads by the process of microencapsulation, enabling the preservation of the entrapped material. The fifth chapter reviews new uses of alginate in the probiotic food industry as a carrier for probiotic immobilization, and summarizes the extrusion and spray dry techniques used to implement them. The sixth chapter gives a brief knowledge of the structure-property relationships, film formation, biocompatibility, and toxicity study of alginate and its different biomedical applications. The seventh and final chapter, after reviewing how alginate is discovered, describes the main properties of alginate, discusses the sources and chemical structure of alginate, and its various applications, especially in drug release and tissue engineering.