Human serum albumin is the most abundant protein in plasma and one of the major binders/carriers of fatty acid and drugs, plays an essential role in pharmacokinetics and delivery of drugs for it transports a wide variety of drugs to target organs and tissues. In the past forty years, the interaction between albumin and compounds is research hotspots both at home and abroad. Furthermore, human serum albumin has been extensively studied as drug carrier. Therefore, this paper first reviews the knowledge on structure of human serum albumin and its complexes, and then puts forward some future challenges on human serum albumin field.

Contents
1 Introduction
2 Structural basis of human serum albumin
2.1 Overall structure of human serum albumin
2.2 Sub-domain structure of human serum albumin
2.3 Cysteine-34 of human serum albumin
3 Structural basis of human serumalbumin-fatty acids
3.1 Binding site of fatty acids at human serum albumin
3.2 Influence of fatty acids on conformation of human serum albumin
4 Structural basis of human serum albumin-drug
4.1 Site Ⅰ
4.2 Site Ⅱ
5 Conclusions and outlook