AbstractPoly(vinyl alcohol)/nano‐silica (PVA/nano‐SiO2) films were prepared through extrusion blowing with the addition of water and glycerin as plasticizer. The characteristic properties of PVA/nano‐SiO2films were investigated by differential scanning calorimetry, dynamic mechanical analysis, Haake torque rheometry, and atomic force microscopy (AFM). The results showed that the mechanical properties of PVA/nano‐SiO2were improved dramatically. The tensile strength of the nanofilms increased from 62 MPa to 104 MPa with loading 0.3 wt % nano‐SiO2and the tear strength was improved from 222 KN/m to 580 KN/m. The crystallinity of the films loaded with 0.4 wt. % nano‐SiO2decreased from 32.2% to 21.0% and the AFM images indicated that the amorphous region of nanofilms increased with increasing nano‐SiO2content. The storage modulus and loss modulus increased to two and nearly three times with 0.3 wt % nano‐SiO2loading. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013