POSS containing graphene oxide-polycaprolactone composite was prepared by using ring opening polymerization. For this purpose, firstly, AmidoPOSS-PDMP was synthesized with aminopropyllsobutyl POSS (POSS-NH2) and protected 2,2-Bis (hydroxymethyl) propionic acid(bis-PDMP). After removal of the acetonide group on AmidoPOSS-PDMP, functionalized POSS (AmidoPOSS-DMP) was obtained. AmidoPOSS-DMP and graphene oxide were reacted to give AmidoPOSS-GO and finally, POSS containing graphene oxide-polycaprolactone composite (AmidoPOSS-GO-PCL) was synthesized by using ?-caprolactone and AmidoPOSS-GO. Tin (II) octanoate was used as catalyst in DMF at 110 ;C. The synthesized compound and polymer composite were characterized by nuclear magnetic resonance (H-1-NMR), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared Spectroscopy (FT-IR). Thermal behaviours of molecules were analysed using Thermogravimetry (TG). The surface morphology of composites was analysed by Scanning Electron Microscope (SEM) and Atomic Force Spectroscopy (AFM). The radiation effects on PCL-GO and AmidoPOSS-GO-PCL composites were investigated by using gamma radiation at 10 kGy absorbed dose.