The book is about the brief study performed on Chitosan derivative produced and prepared from chitin which is the predominant polysaccharide found in crustaceans exoskeleton. The book is highlighting the importance of Chitin and chitin based derivatives as miracle molecules for agriculture and pharmaceuticals.Chitin and its derivatives holds great economic value due to their versatile biological activities and chemical applications, mainly in medical and pharmaceutical areas. These are useful for applications in various fields of agri and medical sciences.