Abstract: This study investigated the effect of different carrier materials on the in vitro properties of progesterone solid dispersions. The solid dispersions of the insoluble drug progesterone were prepared by hot melt extrusion technique using rheological properties as the index of investigation, and the in vitro properties of the solid dispersions were characterized. Scanning electron microscope revealed solid dispersions with rough surfaces and agglomerated microstructures into irregular lumpy particles. Differential scanning calorimetry and powder X-ray diffraction showed the change of progesterone crystalline form in solid dispersions from crystalline to amorphous state. In vitro dissolution studies showed that solid dispersions prepared with different carrier materials can effectively improve the dissolution rate of drugs. The results of the study showed that the type of carrier material had a significant effect on the in vitro properties of solid dispersions, providing a reference for the study of solid dispersions in the controlled release of insoluble drugs.