Polycaprolactone is an organic high molecular polymer with the chemical formula (C6H10O2)n. It has the property of being well soluble in aromatic compounds, ketones and polar solvents. It is produced by ring-opening polymerization of ε-caprolactone in the presence of metal organic compounds (such as tetraphenyltin) as catalyst and dihydroxy or trihydroxy as initiator. It belongs to polymerized polyester, and its molecular weight and disproportionation degree vary with the type and amount of starting materials.