Galactosamine is a hexosamine with a chemical system called 2-amino-2-deoxy-D-galactose. In nature, galactosamine is widely present as a constituent sugar (in the form of N-acetylgalactosamine) of glycoproteins and proteoglycans that constitute the supporting material of animal cells and tissues. Galactosamine can be used to study biological processes such as glycosylation and sugar chain structure, and can also be used to construct targeted drug delivery systems to improve the utilization and efficacy of drugs.