Human Serum Albumin (HSA) is the most abundant plasma protein. It has been widely used for drug delivery systems and has recently emerged as a versatile carrier for therapeutic agents against diabetes, cancer and infectious diseases. This book provides an overview of the expanding field of preclinical and clinical applications and developments that use albumin as a carrier of drug delivery systems. The authors' discuss the properties of drug binding sites within the structure of HSA, discuss new possibilities for the therapeutic potential of HSA and analyze recently reported HSA-drug complexes including HSA-antibody conjugates. Novel investigations on the applications of albumin fusion proteins are discussed as well, with a focus on tumor targeting and intracellular delivery. Other chapters examine the different aspects of albumin glycation and oxidation, the changes in the structure of human serum albumin determined from infrared spectroscopy and a review of CAPIDAN, a special fluorescent dye, which attaches to drug binding sites of human serum albumin.