Abstract: The amorphous solid dispersion is one of the most effective formulation approaches to enhance the oral bioavailability of poorly water-soluble drugs. However, the amorphous drugs tend to crystallize during storage or dissolution due to inadequate formulations, preparation techniques, storage and dissolution conditions, thus negating their advantages. Meanwhile, it is often difficult to establish in vitro-in vivo correlation for amorphous solid dispersions owing to the difference between dissolution media and physiological environments and between the apparent concentration and membrane transport flux, the dynamic process of the in vivo absorption, which put great challenges to the development of amorphous solid dispersion products. This review covers the recent progress on the mechanistic study of the in vitro dissolution and in vivo absorption of amorphous solid dispersions, aiming to provide guidance for the formulation development of poorly soluble drugs.