Two octaisobutyl-polyhedral oligomeric silsesquioxanes (oib-POSS) reinforced biodegradable poly(ε-caprolactone) (PCL) composites were prepared via two different methods,i.e.,melt compounding and solution casting,which were named as mPCL/oib-POSS and sPCL/oib-POSS,respectively,in this work.Oib-POSS dispersed finely in both composites;moreover,oib-POSS aggregates were larger in mPCL/oib-POSS than in sPCL/oib-POSS.Despite the different preparation methods,oib-POSS obviously promoted the crystallization of PCL,especially in sPCL/oib-POSS,but did not modify the crystal structure of PCL.The storage moduli of PCL were improved significantly in both composites.PCL/oib-POSS composites with enhanced crystallization behavior and improved dynamic mechanical properties were successfully prepared through both methods;moreover,the solution casting method was more effective than the melt compounding method.