A series of hybrid materials involving cage-like octaaminopropyl polyhedral oligomeric silsesquioxane and Polyvinyl alcohol(OAPS/PVA) were prepared via solution blending method. The hybrid systems were characterized by FT-IR, scanning electronic microscopy(SEM), energy dispersive X-ray(EDS), differential scanning calorimetry(DSC), thermogravimetry analysis(TGA) and tensile test. The results show that hydrogen bond interactions are formed between OAPS and PVA and OAPS has a good dispersion in PVA matrix. The glass transition temperature(Tg) of OAPS/PVA increases from 53 °C to 61 °C, while the melting temperature(Tm) decreases from 180 °C to 173 °C with increasing OAPS content from 0 % to 12 %. The thermal stability of PVA main chain is improved by the addition of OAPS and the residue ratio also increases. The tensile strength of OAPS/PVA decreases from 39 MPa to 16 MPa, while the elongation at break of hybrid films increases from 148 % to 351 %.